Cleanup code related to SkFlattenable::flatten()

The following changes were made by this CL:

1. Make flatten() a protected method as callers should use
   SkFlattenableWriteBuffer to flatten an object
2. Make flatten a const method (including subclasses)
3. Mark subclass implementation of flatten with SK_OVERRIDE
4. Ensure overridden flatten impls call their parent
5. Remove no-op implementations of flatten from subclasses

Additionally, if necessary the unflattening constructor was
also moved to the protected section of the subclasses
header if it was not already there.

git-svn-id: http://skia.googlecode.com/svn/trunk@3540 2bbb7eff-a529-9590-31e7-b0007b416f81

43 files changed, 109 insertions, 125 deletions

diff --git a/src/animator/SkDrawExtraPathEffect.cpp b/src/animator/SkDrawExtraPathEffect.cpp
index c901df312a..c9de254a65 100644
--- a/src/animator/SkDrawExtraPathEffect.cpp
+++ b/src/animator/SkDrawExtraPathEffect.cpp
@@ -140,8 +140,6 @@ protected:
     }
 
 private:
-    virtual void flatten(SkFlattenableWriteBuffer& ) {}
-
     static bool GetContourLength(const char* token, size_t len, void* clen, SkScriptValue* value) {
         if (SK_LITERAL_STR_EQUAL("contourLength", token, len)) {
             value->fOperand.fScalar = *(SkScalar*) clen;
diff --git a/src/core/SkBitmapProcShader.cpp b/src/core/SkBitmapProcShader.cpp
index e3c46d0ed2..7ae6afca81 100644
--- a/src/core/SkBitmapProcShader.cpp
+++ b/src/core/SkBitmapProcShader.cpp
@@ -68,7 +68,7 @@ SkShader::BitmapType SkBitmapProcShader::asABitmap(SkBitmap* texture,
     return kDefault_BitmapType;
 }
 
-void SkBitmapProcShader::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkBitmapProcShader::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     fRawBitmap.flatten(buffer);
diff --git a/src/core/SkBitmapProcShader.h b/src/core/SkBitmapProcShader.h
index 6140259e6e..26b4cc2ea5 100644
--- a/src/core/SkBitmapProcShader.h
+++ b/src/core/SkBitmapProcShader.h
@@ -36,7 +36,7 @@ public:
 
 protected:
     SkBitmapProcShader(SkFlattenableReadBuffer& );
-    virtual void flatten(SkFlattenableWriteBuffer& );
+    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
 
     SkBitmap          fRawBitmap;   // experimental for RLE encoding
     SkBitmapProcState fState;
diff --git a/src/core/SkBlitter.cpp b/src/core/SkBlitter.cpp
index 2ce0197d24..735ad0431f 100644
--- a/src/core/SkBlitter.cpp
+++ b/src/core/SkBlitter.cpp
@@ -659,14 +659,13 @@ public:
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(Sk3DShader)
 
 protected:
-    Sk3DShader(SkFlattenableReadBuffer& buffer) :
-            INHERITED(buffer) {
+    Sk3DShader(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
         fProxy = static_cast<SkShader*>(buffer.readFlattenable());
         fPMColor = buffer.readU32();
         fMask = NULL;
     }
 
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) {
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.writeFlattenable(fProxy);
         buffer.write32(fPMColor);
diff --git a/src/core/SkColorFilter.cpp b/src/core/SkColorFilter.cpp
index 2ca88bb7a2..b96b77ea23 100644
--- a/src/core/SkColorFilter.cpp
+++ b/src/core/SkColorFilter.cpp
@@ -66,7 +66,7 @@ void SkFilterShader::endSession() {
     this->INHERITED::endSession();
 }
 
-void SkFilterShader::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkFilterShader::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeFlattenable(fShader);
     buffer.writeFlattenable(fFilter);
diff --git a/src/core/SkComposeShader.cpp b/src/core/SkComposeShader.cpp
index c8d329914e..6f3eccd5e0 100644
--- a/src/core/SkComposeShader.cpp
+++ b/src/core/SkComposeShader.cpp
@@ -70,7 +70,7 @@ private:
     uint8_t     fAlpha;
 };
 
-void SkComposeShader::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkComposeShader::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeFlattenable(fShaderA);
     buffer.writeFlattenable(fShaderB);
diff --git a/src/core/SkFlattenable.cpp b/src/core/SkFlattenable.cpp
index 9d8c215a8c..6a445ea751 100644
--- a/src/core/SkFlattenable.cpp
+++ b/src/core/SkFlattenable.cpp
@@ -37,7 +37,7 @@ void SkWriteRegion(SkWriter32* writer, const SkRegion& rgn) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void SkFlattenable::flatten(SkFlattenableWriteBuffer&)
+void SkFlattenable::flatten(SkFlattenableWriteBuffer&) const
 {
     /*  we don't write anything at the moment, but this allows our subclasses
         to not know that, since we want them to always call INHERITED::flatten()
diff --git a/src/core/SkMallocPixelRef.cpp b/src/core/SkMallocPixelRef.cpp
index 1cf64a1db0..313a26eeaa 100644
--- a/src/core/SkMallocPixelRef.cpp
+++ b/src/core/SkMallocPixelRef.cpp
@@ -34,7 +34,7 @@ void SkMallocPixelRef::onUnlockPixels() {
     // nothing to do
 }
 
-void SkMallocPixelRef::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkMallocPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.write32(fSize);
diff --git a/src/core/SkPathEffect.cpp b/src/core/SkPathEffect.cpp
index 0c0143da46..bbf6f18a23 100644
--- a/src/core/SkPathEffect.cpp
+++ b/src/core/SkPathEffect.cpp
@@ -29,7 +29,8 @@ SkPairPathEffect::~SkPairPathEffect() {
 /*
     Format: [oe0-factory][pe1-factory][pe0-size][pe0-data][pe1-data]
 */
-void SkPairPathEffect::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkPairPathEffect::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
     buffer.writeFlattenable(fPE0);
     buffer.writeFlattenable(fPE1);
 }
@@ -108,7 +109,8 @@ bool SkStrokePathEffect::filterPath(SkPath* dst, const SkPath& src,
     return true;
 }
 
-void SkStrokePathEffect::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkStrokePathEffect::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
     buffer.writeScalar(fWidth);
     buffer.writeScalar(fMiter);
     buffer.write8(fStyle);
diff --git a/src/core/SkPixelRef.cpp b/src/core/SkPixelRef.cpp
index 2d4daae781..f01fbea81d 100644
--- a/src/core/SkPixelRef.cpp
+++ b/src/core/SkPixelRef.cpp
@@ -49,7 +49,7 @@ SkPixelRef::SkPixelRef(SkFlattenableReadBuffer& buffer, SkBaseMutex* mutex)
     fIsImmutable = buffer.readBool();
 }
 
-void SkPixelRef::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeBool(fIsImmutable);
 }
diff --git a/src/core/SkRasterizer.cpp b/src/core/SkRasterizer.cpp
index 7ccced8a7a..d5023b3044 100644
--- a/src/core/SkRasterizer.cpp
+++ b/src/core/SkRasterizer.cpp
@@ -12,9 +12,6 @@
 #include "SkMaskFilter.h"
 #include "SkPath.h"
 
-// do nothing for now, since we don't store anything at flatten time
-SkRasterizer::SkRasterizer(SkFlattenableReadBuffer&) {}
-
 bool SkRasterizer::rasterize(const SkPath& fillPath, const SkMatrix& matrix,
                              const SkIRect* clipBounds, SkMaskFilter* filter,
                              SkMask* mask, SkMask::CreateMode mode) {
diff --git a/src/core/SkShader.cpp b/src/core/SkShader.cpp
index a3b3b6a216..bfdebc1b07 100644
--- a/src/core/SkShader.cpp
+++ b/src/core/SkShader.cpp
@@ -41,7 +41,7 @@ void SkShader::endSession() {
     SkDEBUGCODE(fInSession = false;)
 }
 
-void SkShader::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkShader::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeBool(fLocalMatrix != NULL);
     if (fLocalMatrix) {
@@ -238,7 +238,7 @@ SkColorShader::SkColorShader(SkFlattenableReadBuffer& b) : INHERITED(b) {
     fColor = b.readU32();
 }
 
-void SkColorShader::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkColorShader::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.write8(fInheritColor);
     if (fInheritColor) {
@@ -331,8 +331,6 @@ SK_DEFINE_FLATTENABLE_REGISTRAR(SkColorShader)
 
 #include "SkEmptyShader.h"
 
-SkEmptyShader::SkEmptyShader(SkFlattenableReadBuffer& b) : INHERITED(b) {}
-
 uint32_t SkEmptyShader::getFlags() { return 0; }
 uint8_t SkEmptyShader::getSpan16Alpha() const { return 0; }
 
@@ -351,8 +349,4 @@ void SkEmptyShader::shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) {
     SkDEBUGFAIL("should never get called, since setContext() returned false");
 }
 
-void SkEmptyShader::flatten(SkFlattenableWriteBuffer& buffer) {
-    this->INHERITED::flatten(buffer);
-}
-
 SK_DEFINE_FLATTENABLE_REGISTRAR(SkEmptyShader)
diff --git a/src/core/SkShape.cpp b/src/core/SkShape.cpp
index 0c4907e0e0..c386af8990 100644
--- a/src/core/SkShape.cpp
+++ b/src/core/SkShape.cpp
@@ -60,10 +60,6 @@ SkShape::SkShape(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
     inc_shape(this);
 }
 
-void SkShape::flatten(SkFlattenableWriteBuffer& buffer) {
-    this->INHERITED::flatten(buffer);
-}
-
 void SkShape::onDraw(SkCanvas*) {}
 
 SK_DEFINE_FLATTENABLE_REGISTRAR(SkShape)
diff --git a/src/core/SkXfermode.cpp b/src/core/SkXfermode.cpp
index bcb721d35f..62e62a17c1 100644
--- a/src/core/SkXfermode.cpp
+++ b/src/core/SkXfermode.cpp
@@ -685,7 +685,8 @@ SkProcXfermode::SkProcXfermode(SkFlattenableReadBuffer& buffer)
     fProc = (SkXfermodeProc)buffer.readFunctionPtr();
 }
 
-void SkProcXfermode::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkProcXfermode::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
     if (buffer.isCrossProcess()) {
         // function pointer is only valid in the current process. Write a NULL
         // so it can't be accidentally used
@@ -729,16 +730,10 @@ public:
         return true;
     }
 
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) {
-        this->INHERITED::flatten(buffer);
-        buffer.write32(fMode);
-    }
-
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkProcCoeffXfermode)
 
 protected:
-    SkProcCoeffXfermode(SkFlattenableReadBuffer& buffer)
-            : INHERITED(buffer) {
+    SkProcCoeffXfermode(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
         fMode = (SkXfermode::Mode)buffer.readU32();
 
         const ProcCoeff& rec = gProcCoeffs[fMode];
@@ -749,6 +744,11 @@ protected:
         this->INHERITED::setProc(rec.fProc);
     }
 
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
+        this->INHERITED::flatten(buffer);
+        buffer.write32(fMode);
+    }
+
 private:
     Mode    fMode;
     Coeff   fSrcCoeff, fDstCoeff;
diff --git a/src/effects/Sk1DPathEffect.cpp b/src/effects/Sk1DPathEffect.cpp
index 11170f4a46..62ca7b39b8 100644
--- a/src/effects/Sk1DPathEffect.cpp
+++ b/src/effects/Sk1DPathEffect.cpp
@@ -156,7 +156,8 @@ SkScalar SkPath1DPathEffect::begin(SkScalar contourLength) {
     return fInitialOffset;
 }
 
-void SkPath1DPathEffect::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkPath1DPathEffect::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
     buffer.writeScalar(fAdvance);
     if (fAdvance > 0) {
         fPath.flatten(buffer);
diff --git a/src/effects/Sk2DPathEffect.cpp b/src/effects/Sk2DPathEffect.cpp
index 60ec2576d3..9a9216215a 100644
--- a/src/effects/Sk2DPathEffect.cpp
+++ b/src/effects/Sk2DPathEffect.cpp
@@ -64,7 +64,8 @@ void Sk2DPathEffect::end(SkPath* dst) {}
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void Sk2DPathEffect::flatten(SkFlattenableWriteBuffer& buffer) {
+void Sk2DPathEffect::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
     char storage[SkMatrix::kMaxFlattenSize];
     uint32_t size = fMatrix.flatten(storage);
     buffer.write32(size);
@@ -92,7 +93,7 @@ SkPath2DPathEffect::SkPath2DPathEffect(SkFlattenableReadBuffer& buffer)
     fPath.unflatten(buffer);
 }
 
-void SkPath2DPathEffect::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkPath2DPathEffect::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     fPath.flatten(buffer);
 }
diff --git a/src/effects/SkAvoidXfermode.cpp b/src/effects/SkAvoidXfermode.cpp
index d6682226ca..b5375e602f 100644
--- a/src/effects/SkAvoidXfermode.cpp
+++ b/src/effects/SkAvoidXfermode.cpp
@@ -29,7 +29,7 @@ SkAvoidXfermode::SkAvoidXfermode(SkFlattenableReadBuffer& buffer)
     fMode = (Mode)buffer.readU8();
 }
 
-void SkAvoidXfermode::flatten(SkFlattenableWriteBuffer& buffer)
+void SkAvoidXfermode::flatten(SkFlattenableWriteBuffer& buffer) const
 {
     this->INHERITED::flatten(buffer);
 
diff --git a/src/effects/SkBlurDrawLooper.cpp b/src/effects/SkBlurDrawLooper.cpp
index 656f8f7d6c..3b785731fa 100644
--- a/src/effects/SkBlurDrawLooper.cpp
+++ b/src/effects/SkBlurDrawLooper.cpp
@@ -61,7 +61,8 @@ SkBlurDrawLooper::~SkBlurDrawLooper() {
     SkSafeUnref(fColorFilter);
 }
 
-void SkBlurDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkBlurDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
     buffer.writeScalar(fDx);
     buffer.writeScalar(fDy);
     buffer.write32(fBlurColor);
diff --git a/src/effects/SkBlurImageFilter.cpp b/src/effects/SkBlurImageFilter.cpp
index 1446e92117..522f4b05ea 100644
--- a/src/effects/SkBlurImageFilter.cpp
+++ b/src/effects/SkBlurImageFilter.cpp
@@ -24,7 +24,7 @@ bool SkBlurImageFilter::asABlur(SkSize* sigma) const {
     return true;
 }
 
-void SkBlurImageFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkBlurImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fSigma.fWidth);
     buffer.writeScalar(fSigma.fHeight);
diff --git a/src/effects/SkBlurMaskFilter.cpp b/src/effects/SkBlurMaskFilter.cpp
index eb64000007..306770bb65 100644
--- a/src/effects/SkBlurMaskFilter.cpp
+++ b/src/effects/SkBlurMaskFilter.cpp
@@ -24,9 +24,6 @@ public:
     virtual BlurType asABlur(BlurInfo*) const SK_OVERRIDE;
     virtual void computeFastBounds(const SkRect& src, SkRect* dst) SK_OVERRIDE;
 
-    // overrides from SkFlattenable
-    virtual void flatten(SkFlattenableWriteBuffer&) SK_OVERRIDE;
-
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBlurMaskFilterImpl)
 
 private:
@@ -35,6 +32,7 @@ private:
     uint32_t                    fBlurFlags;
 
     SkBlurMaskFilterImpl(SkFlattenableReadBuffer&);
+    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
     
     typedef SkMaskFilter INHERITED;
 };
@@ -112,7 +110,7 @@ SkBlurMaskFilterImpl::SkBlurMaskFilterImpl(SkFlattenableReadBuffer& buffer)
     SkASSERT((unsigned)fBlurStyle < SkBlurMaskFilter::kBlurStyleCount);
 }
 
-void SkBlurMaskFilterImpl::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkBlurMaskFilterImpl::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fRadius);
     buffer.write32(fBlurStyle);
diff --git a/src/effects/SkColorFilters.cpp b/src/effects/SkColorFilters.cpp
index 2970c7c218..3b97250930 100644
--- a/src/effects/SkColorFilters.cpp
+++ b/src/effects/SkColorFilters.cpp
@@ -50,7 +50,7 @@ public:
     bool isModeValid() const { return ILLEGAL_XFERMODE_MODE != fMode; }
 
 protected:
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) {
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.write32(fColor);
         buffer.write32(fMode);
@@ -193,7 +193,7 @@ public:
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(Proc_SkModeColorFilter)
 
 protected:
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) {
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.writeFunctionPtr((void*)fProc);
         buffer.writeFunctionPtr((void*)fProc16);
@@ -312,7 +312,7 @@ public:
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLightingColorFilter)
 
 protected:
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) {
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.write32(fMul);
         buffer.write32(fAdd);
@@ -489,7 +489,7 @@ protected:
         }
     }
 
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) {}
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {}
 
     virtual Factory getFactory() {
         return CreateProc;
diff --git a/src/effects/SkColorMatrixFilter.cpp b/src/effects/SkColorMatrixFilter.cpp
index 47ff8ad6ac..c6886250fa 100644
--- a/src/effects/SkColorMatrixFilter.cpp
+++ b/src/effects/SkColorMatrixFilter.cpp
@@ -310,7 +310,7 @@ void SkColorMatrixFilter::filterSpan16(const uint16_t src[], int count,
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void SkColorMatrixFilter::flatten(SkFlattenableWriteBuffer& buffer)  {
+void SkColorMatrixFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.writeFunctionPtr((void*)fProc);
diff --git a/src/effects/SkCornerPathEffect.cpp b/src/effects/SkCornerPathEffect.cpp
index 5eb94a438f..bf59a27a1b 100644
--- a/src/effects/SkCornerPathEffect.cpp
+++ b/src/effects/SkCornerPathEffect.cpp
@@ -129,7 +129,8 @@ DONE:
     return true;
 }
 
-void SkCornerPathEffect::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkCornerPathEffect::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
     buffer.writeScalar(fRadius);
 }
 
diff --git a/src/effects/SkDashPathEffect.cpp b/src/effects/SkDashPathEffect.cpp
index 7950d648af..88f003b4af 100644
--- a/src/effects/SkDashPathEffect.cpp
+++ b/src/effects/SkDashPathEffect.cpp
@@ -140,9 +140,10 @@ SkFlattenable::Factory SkDashPathEffect::getFactory() {
     return fInitialDashLength < 0 ? NULL : CreateProc;
 }
 
-void SkDashPathEffect::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkDashPathEffect::flatten(SkFlattenableWriteBuffer& buffer) const {
     SkASSERT(fInitialDashLength >= 0);
 
+    this->INHERITED::flatten(buffer);
     buffer.write32(fCount);
     buffer.write32(fInitialDashIndex);
     buffer.writeScalar(fInitialDashLength);
diff --git a/src/effects/SkDiscretePathEffect.cpp b/src/effects/SkDiscretePathEffect.cpp
index 089bed6757..e8c0ec9ad2 100644
--- a/src/effects/SkDiscretePathEffect.cpp
+++ b/src/effects/SkDiscretePathEffect.cpp
@@ -67,7 +67,8 @@ bool SkDiscretePathEffect::filterPath(SkPath* dst, const SkPath& src,
     return true;
 }
 
-void SkDiscretePathEffect::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkDiscretePathEffect::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
     buffer.writeScalar(fSegLength);
     buffer.writeScalar(fPerterb);
 }
diff --git a/src/effects/SkEmbossMaskFilter.cpp b/src/effects/SkEmbossMaskFilter.cpp
index 26a5e2ec59..245ccd69df 100644
--- a/src/effects/SkEmbossMaskFilter.cpp
+++ b/src/effects/SkEmbossMaskFilter.cpp
@@ -122,11 +122,12 @@ SkEmbossMaskFilter::SkEmbossMaskFilter(SkFlattenableReadBuffer& buffer)
     fBlurRadius = buffer.readScalar();
 }
 
-void SkEmbossMaskFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkEmbossMaskFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
-    fLight.fPad = 0;    // for the font-cache lookup to be clean
-    buffer.writeMul4(&fLight, sizeof(fLight));
+    Light tmpLight = fLight;
+    tmpLight.fPad = 0;    // for the font-cache lookup to be clean
+    buffer.writeMul4(&tmpLight, sizeof(tmpLight));
     buffer.writeScalar(fBlurRadius);
 }
 
diff --git a/src/effects/SkGradientShader.cpp b/src/effects/SkGradientShader.cpp
index 0fcb514585..a93bd52dbb 100644
--- a/src/effects/SkGradientShader.cpp
+++ b/src/effects/SkGradientShader.cpp
@@ -174,6 +174,8 @@ public:
 
 protected:
     Gradient_Shader(SkFlattenableReadBuffer& );
+    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
+
     SkUnitMapper* fMapper;
     SkMatrix    fPtsToUnit;     // set by subclass
     SkMatrix    fDstToIndex;
@@ -190,7 +192,6 @@ protected:
     };
     Rec*        fRecs;
 
-    virtual void flatten(SkFlattenableWriteBuffer& );
     const uint16_t*     getCache16() const;
     const SkPMColor*    getCache32() const;
 
@@ -404,7 +405,7 @@ void Gradient_Shader::initCommon() {
     fColorsAreOpaque = colorAlpha == 0xFF;
 }
 
-void Gradient_Shader::flatten(SkFlattenableWriteBuffer& buffer) {
+void Gradient_Shader::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeFlattenable(fMapper);
     buffer.write32(fColorCount);
@@ -849,22 +850,21 @@ public:
                              SkScalar* twoPointRadialParams) const SK_OVERRIDE;
     virtual GradientType asAGradient(GradientInfo* info) const SK_OVERRIDE;
 
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) SK_OVERRIDE {
-        this->INHERITED::flatten(buffer);
-        buffer.writeScalar(fStart.fX);
-        buffer.writeScalar(fStart.fY);
-        buffer.writeScalar(fEnd.fX);
-        buffer.writeScalar(fEnd.fY);
-    }
-
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(Linear_Gradient)
 
 protected:
     Linear_Gradient(SkFlattenableReadBuffer& buffer)
-        : Gradient_Shader(buffer),
+        : INHERITED(buffer),
           fStart(unflatten_point(buffer)),
           fEnd(unflatten_point(buffer)) {
     }
+    virtual void flatten(SkFlattenableWriteBuffer& buffer)  const SK_OVERRIDE {
+        this->INHERITED::flatten(buffer);
+        buffer.writeScalar(fStart.fX);
+        buffer.writeScalar(fStart.fY);
+        buffer.writeScalar(fEnd.fX);
+        buffer.writeScalar(fEnd.fY);
+    }
 
 private:
     typedef Gradient_Shader INHERITED;
@@ -1507,21 +1507,20 @@ public:
         return kRadial_GradientType;
     }
 
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) SK_OVERRIDE {
-        this->INHERITED::flatten(buffer);
-        buffer.writeScalar(fCenter.fX);
-        buffer.writeScalar(fCenter.fY);
-        buffer.writeScalar(fRadius);
-    }
-
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(Radial_Gradient)
 
 protected:
     Radial_Gradient(SkFlattenableReadBuffer& buffer)
-        : Gradient_Shader(buffer),
+        : INHERITED(buffer),
           fCenter(unflatten_point(buffer)),
           fRadius(buffer.readScalar()) {
     }
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
+        this->INHERITED::flatten(buffer);
+        buffer.writeScalar(fCenter.fX);
+        buffer.writeScalar(fCenter.fY);
+        buffer.writeScalar(fRadius);
+    }
 
 private:
     typedef Gradient_Shader INHERITED;
@@ -2039,21 +2038,11 @@ public:
         return true;
     }
 
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) SK_OVERRIDE {
-        this->INHERITED::flatten(buffer);
-        buffer.writeScalar(fCenter1.fX);
-        buffer.writeScalar(fCenter1.fY);
-        buffer.writeScalar(fCenter2.fX);
-        buffer.writeScalar(fCenter2.fY);
-        buffer.writeScalar(fRadius1);
-        buffer.writeScalar(fRadius2);
-    }
-
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(Two_Point_Radial_Gradient)
 
 protected:
     Two_Point_Radial_Gradient(SkFlattenableReadBuffer& buffer)
-            : Gradient_Shader(buffer),
+            : INHERITED(buffer),
               fCenter1(unflatten_point(buffer)),
               fCenter2(unflatten_point(buffer)),
               fRadius1(buffer.readScalar()),
@@ -2061,6 +2050,16 @@ protected:
         init();
     };
 
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
+        this->INHERITED::flatten(buffer);
+        buffer.writeScalar(fCenter1.fX);
+        buffer.writeScalar(fCenter1.fY);
+        buffer.writeScalar(fCenter2.fX);
+        buffer.writeScalar(fCenter2.fY);
+        buffer.writeScalar(fRadius1);
+        buffer.writeScalar(fRadius2);
+    }
+
 private:
     typedef Gradient_Shader INHERITED;
     const SkPoint fCenter1;
@@ -2125,19 +2124,18 @@ public:
         return kSweep_GradientType;
     }
 
-    virtual void flatten(SkFlattenableWriteBuffer& buffer) SK_OVERRIDE {
-        this->INHERITED::flatten(buffer);
-        buffer.writeScalar(fCenter.fX);
-        buffer.writeScalar(fCenter.fY);
-    }
-
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(Sweep_Gradient)
 
 protected:
     Sweep_Gradient(SkFlattenableReadBuffer& buffer)
-        : Gradient_Shader(buffer),
+        : INHERITED(buffer),
           fCenter(unflatten_point(buffer)) {
     }
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
+        this->INHERITED::flatten(buffer);
+        buffer.writeScalar(fCenter.fX);
+        buffer.writeScalar(fCenter.fY);
+    }
 
 private:
     typedef Gradient_Shader INHERITED;
diff --git a/src/effects/SkGroupShape.cpp b/src/effects/SkGroupShape.cpp
index b27026e8b9..83a204396f 100644
--- a/src/effects/SkGroupShape.cpp
+++ b/src/effects/SkGroupShape.cpp
@@ -83,7 +83,7 @@ void SkGroupShape::onDraw(SkCanvas* canvas) {
     }
 }
 
-void SkGroupShape::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkGroupShape::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     int count = fList.count();
diff --git a/src/effects/SkKernel33MaskFilter.cpp b/src/effects/SkKernel33MaskFilter.cpp
index f01451c4fe..10aabc4e77 100644
--- a/src/effects/SkKernel33MaskFilter.cpp
+++ b/src/effects/SkKernel33MaskFilter.cpp
@@ -73,7 +73,7 @@ bool SkKernel33ProcMaskFilter::filterMask(SkMask* dst, const SkMask& src,
     return true;
 }
 
-void SkKernel33ProcMaskFilter::flatten(SkFlattenableWriteBuffer& wb) {
+void SkKernel33ProcMaskFilter::flatten(SkFlattenableWriteBuffer& wb) const {
     this->INHERITED::flatten(wb);
     wb.write32(fPercent256);
 }
@@ -104,7 +104,7 @@ uint8_t SkKernel33MaskFilter::computeValue(uint8_t* const* srcRows) {
     return (uint8_t)value;
 }
 
-void SkKernel33MaskFilter::flatten(SkFlattenableWriteBuffer& wb) {
+void SkKernel33MaskFilter::flatten(SkFlattenableWriteBuffer& wb) const {
     this->INHERITED::flatten(wb);
     wb.writeMul4(fKernel, 9 * sizeof(int));
     wb.write32(fShift);
diff --git a/src/effects/SkLayerDrawLooper.cpp b/src/effects/SkLayerDrawLooper.cpp
index acb3e8891f..250306ca16 100644
--- a/src/effects/SkLayerDrawLooper.cpp
+++ b/src/effects/SkLayerDrawLooper.cpp
@@ -180,7 +180,7 @@ SkLayerDrawLooper::Rec* SkLayerDrawLooper::Rec::Reverse(Rec* head) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void SkLayerDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkLayerDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
 #ifdef SK_DEBUG
diff --git a/src/effects/SkLayerRasterizer.cpp b/src/effects/SkLayerRasterizer.cpp
index ae4eb2eb99..81263d13d1 100644
--- a/src/effects/SkLayerRasterizer.cpp
+++ b/src/effects/SkLayerRasterizer.cpp
@@ -197,7 +197,7 @@ SkLayerRasterizer::SkLayerRasterizer(SkFlattenableReadBuffer& buffer)
     }
 }
 
-void SkLayerRasterizer::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkLayerRasterizer::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.write32(fLayers.count());
diff --git a/src/effects/SkMorphologyImageFilter.cpp b/src/effects/SkMorphologyImageFilter.cpp
index 78fabc5616..09610cd145 100644
--- a/src/effects/SkMorphologyImageFilter.cpp
+++ b/src/effects/SkMorphologyImageFilter.cpp
@@ -19,7 +19,7 @@ SkMorphologyImageFilter::SkMorphologyImageFilter(int radiusX, int radiusY)
 }
 
 
-void SkMorphologyImageFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkMorphologyImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fRadius.fWidth);
     buffer.writeScalar(fRadius.fHeight);
diff --git a/src/effects/SkPixelXorXfermode.cpp b/src/effects/SkPixelXorXfermode.cpp
index b4bbaf970c..7b58ed76a8 100644
--- a/src/effects/SkPixelXorXfermode.cpp
+++ b/src/effects/SkPixelXorXfermode.cpp
@@ -18,13 +18,13 @@ SkPMColor SkPixelXorXfermode::xferColor(SkPMColor src, SkPMColor dst) {
     return res;
 }
 
-void SkPixelXorXfermode::flatten(SkFlattenableWriteBuffer& wb) {
+void SkPixelXorXfermode::flatten(SkFlattenableWriteBuffer& wb) const {
     this->INHERITED::flatten(wb);
     wb.write32(fOpColor);
 }
 
 SkPixelXorXfermode::SkPixelXorXfermode(SkFlattenableReadBuffer& rb)
-        : SkXfermode(rb) {
+        : INHERITED(rb) {
     fOpColor = rb.readU32();
 }
 
diff --git a/src/effects/SkRectShape.cpp b/src/effects/SkRectShape.cpp
index d7e2628832..68d1e1f7ff 100644
--- a/src/effects/SkRectShape.cpp
+++ b/src/effects/SkRectShape.cpp
@@ -60,7 +60,7 @@ void SkRectShape::onDraw(SkCanvas* canvas) {
     }
 }
 
-void SkRectShape::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkRectShape::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.writeRect(fBounds);
@@ -74,7 +74,7 @@ SkRectShape::SkRectShape(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void SkPaintShape::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkPaintShape::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     
     fPaint.flatten(buffer);
diff --git a/src/effects/SkTableColorFilter.cpp b/src/effects/SkTableColorFilter.cpp
index 8b60326b40..c709dd495a 100644
--- a/src/effects/SkTableColorFilter.cpp
+++ b/src/effects/SkTableColorFilter.cpp
@@ -35,12 +35,12 @@ public:
 
     virtual void filterSpan(const SkPMColor src[], int count,
                             SkPMColor dst[]) SK_OVERRIDE;
-    virtual void flatten(SkFlattenableWriteBuffer&) SK_OVERRIDE;
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTable_ColorFilter)
 
 protected:
     SkTable_ColorFilter(SkFlattenableReadBuffer& buffer);
+    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
 
 private:
     SkBitmap* fBitmap;
@@ -145,7 +145,7 @@ static const uint8_t gCountNibBits[] = {
 
 #include "SkPackBits.h"
 
-void SkTable_ColorFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkTable_ColorFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     uint8_t storage[5*256];
diff --git a/src/effects/SkTableMaskFilter.cpp b/src/effects/SkTableMaskFilter.cpp
index 3a3d0e596a..fed0c5da72 100644
--- a/src/effects/SkTableMaskFilter.cpp
+++ b/src/effects/SkTableMaskFilter.cpp
@@ -71,7 +71,7 @@ SkMask::Format SkTableMaskFilter::getFormat() {
     return SkMask::kA8_Format;
 }
 
-void SkTableMaskFilter::flatten(SkFlattenableWriteBuffer& wb) {
+void SkTableMaskFilter::flatten(SkFlattenableWriteBuffer& wb) const {
     this->INHERITED::flatten(wb);
     wb.writePad(fTable, 256);
 }
diff --git a/src/effects/SkTestImageFilters.cpp b/src/effects/SkTestImageFilters.cpp
index 688e298cc1..0dd360b476 100755
--- a/src/effects/SkTestImageFilters.cpp
+++ b/src/effects/SkTestImageFilters.cpp
@@ -32,7 +32,7 @@ bool SkOffsetImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm
     return true;
 }
 
-void SkOffsetImageFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkOffsetImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fOffset.x());
     buffer.writeScalar(fOffset.y());
@@ -84,7 +84,7 @@ bool SkComposeImageFilter::onFilterBounds(const SkIRect& src,
            fOuter->filterBounds(tmp, ctm, dst);
 }
 
-void SkComposeImageFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkComposeImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.writeFlattenable(fOuter);
@@ -238,7 +238,7 @@ bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
     return true;
 }
 
-void SkMergeImageFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkMergeImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     int storedCount = fCount;
@@ -307,7 +307,7 @@ bool SkColorFilterImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
     return true;
 }
 
-void SkColorFilterImageFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkColorFilterImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     
     buffer.writeFlattenable(fColorFilter);
@@ -369,7 +369,7 @@ bool SkDownSampleImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
     return true;
 }
 
-void SkDownSampleImageFilter::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkDownSampleImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     
     buffer.writeScalar(fScale);
diff --git a/src/effects/SkTransparentShader.cpp b/src/effects/SkTransparentShader.cpp
index c827c111c0..28b075f4e2 100644
--- a/src/effects/SkTransparentShader.cpp
+++ b/src/effects/SkTransparentShader.cpp
@@ -125,8 +125,3 @@ void SkTransparentShader::shadeSpan16(int x, int y, uint16_t span[], int count)
         memcpy(span, src, count << 1);
     }
 }
-
-void SkTransparentShader::flatten(SkFlattenableWriteBuffer& buffer) {
-    this->INHERITED::flatten(buffer);
-}
-
diff --git a/src/images/SkFlipPixelRef.cpp b/src/images/SkFlipPixelRef.cpp
index 768a67dc4f..6ab5bbc68f 100644
--- a/src/images/SkFlipPixelRef.cpp
+++ b/src/images/SkFlipPixelRef.cpp
@@ -60,7 +60,7 @@ void SkFlipPixelRef::swapPages() {
     fMutex.release();
 }
 
-void SkFlipPixelRef::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkFlipPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     
     buffer.write32(fSize);
diff --git a/src/images/SkImageRef.cpp b/src/images/SkImageRef.cpp
index cdd80e76c3..1d6b270d6c 100644
--- a/src/images/SkImageRef.cpp
+++ b/src/images/SkImageRef.cpp
@@ -189,7 +189,7 @@ SkImageRef::SkImageRef(SkFlattenableReadBuffer& buffer)
     fFactory = NULL;
 }
 
-void SkImageRef::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkImageRef::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.write8(fConfig);
diff --git a/src/ports/SkImageRef_ashmem.cpp b/src/ports/SkImageRef_ashmem.cpp
index a9208e8680..f1fb829fc9 100644
--- a/src/ports/SkImageRef_ashmem.cpp
+++ b/src/ports/SkImageRef_ashmem.cpp
@@ -210,7 +210,7 @@ void SkImageRef_ashmem::onUnlockPixels() {
     fBitmap.setPixels(NULL, NULL);
 }
 
-void SkImageRef_ashmem::flatten(SkFlattenableWriteBuffer& buffer) {
+void SkImageRef_ashmem::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     const char* uri = getURI();
     if (uri) {
diff --git a/src/ports/SkImageRef_ashmem.h b/src/ports/SkImageRef_ashmem.h
index 38442f6ce8..5b4e8142dc 100644
--- a/src/ports/SkImageRef_ashmem.h
+++ b/src/ports/SkImageRef_ashmem.h
@@ -22,11 +22,12 @@ public:
     SkImageRef_ashmem(SkStream*, SkBitmap::Config, int sampleSize = 1);
     virtual ~SkImageRef_ashmem();
     
-    // overrides
-    virtual void flatten(SkFlattenableWriteBuffer&);
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkImageRef_ashmem)
 
 protected:
+    SkImageRef_ashmem(SkFlattenableReadBuffer&);
+    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
+
     virtual bool onDecode(SkImageDecoder* codec, SkStream* stream,
                           SkBitmap* bitmap, SkBitmap::Config config,
                           SkImageDecoder::Mode mode);
@@ -35,7 +36,6 @@ protected:
     virtual void onUnlockPixels();
     
 private:
-    SkImageRef_ashmem(SkFlattenableReadBuffer&);
     void closeFD();
 
     SkColorTable* fCT;
diff --git a/src/utils/SkUnitMappers.cpp b/src/utils/SkUnitMappers.cpp
index dd238809fe..df9771d538 100644
--- a/src/utils/SkUnitMappers.cpp
+++ b/src/utils/SkUnitMappers.cpp
@@ -33,7 +33,7 @@ SkDiscreteMapper::SkDiscreteMapper(SkFlattenableReadBuffer& rb)
     fScale = rb.readU32();
 }
 
-void SkDiscreteMapper::flatten(SkFlattenableWriteBuffer& wb) {
+void SkDiscreteMapper::flatten(SkFlattenableWriteBuffer& wb) const {
     this->INHERITED::flatten(wb);
 
     wb.write32(fSegments);