Revert "Remove support for decoding to kIndex_8"

This reverts commit 742a3e298fda669006147e4a305bab8452369b1f.

Reason for revert: Breaking Android roll:
frameworks/base/core/jni/android/graphics/BitmapFactory.cpp:453:18: error: no member named 'fColorPtr' in 'SkAndroidCodec::AndroidOptions'
    codecOptions.fColorPtr = colorPtr;
    ~~~~~~~~~~~~ ^
frameworks/base/core/jni/android/graphics/BitmapFactory.cpp:454:18: error: no member named 'fColorCount' in 'SkAndroidCodec::AndroidOptions'
    codecOptions.fColorCount = colorCount;
    ~~~~~~~~~~~~ ^

Original change's description:
> Remove support for decoding to kIndex_8
> 
> Fix up callsites, and remove tests that no longer make sense.
> 
> Bug: skia:6828
> Change-Id: I2548c4b7528b7b1be7412563156f27b52c9d4295
> Reviewed-on: https://skia-review.googlesource.com/21664
> Reviewed-by: Derek Sollenberger <djsollen@google.com>
> Commit-Queue: Leon Scroggins <scroggo@google.com>

TBR=djsollen@google.com,scroggo@google.com

Change-Id: I1bc669441f250690884e75a9a61427fdf75c6907
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:6828
Reviewed-on: https://skia-review.googlesource.com/22120
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>

3 files changed, 74 insertions, 17 deletions

diff --git a/include/codec/SkAndroidCodec.h b/include/codec/SkAndroidCodec.h
index b4dd3854e6..87d514dfff 100644
--- a/include/codec/SkAndroidCodec.h
+++ b/include/codec/SkAndroidCodec.h
@@ -57,7 +57,7 @@ public:
      *  @param requestedColorType Color type requested by the client
      *
      *  |requestedColorType| may be overriden.  We will default to kF16
-     *  for high precision images.
+     *  for high precision images and kIndex8 for GIF and WBMP.
      *
      *  In the general case, if it is possible to decode to
      *  |requestedColorType|, this returns |requestedColorType|.
@@ -154,6 +154,8 @@ public:
         AndroidOptions()
             : fZeroInitialized(SkCodec::kNo_ZeroInitialized)
             , fSubset(nullptr)
+            , fColorPtr(nullptr)
+            , fColorCount(nullptr)
             , fSampleSize(1)
         {}
 
@@ -177,6 +179,22 @@ public:
         SkIRect* fSubset;
 
         /**
+         *  If the client has requested a decode to kIndex8_SkColorType
+         *  (specified in the SkImageInfo), then the caller must provide
+         *  storage for up to 256 SkPMColor values in fColorPtr.  On success,
+         *  the codec must copy N colors into that storage, (where N is the
+         *  logical number of table entries) and set fColorCount to N.
+         *
+         *  If the client does not request kIndex8_SkColorType, then the last
+         *  two parameters may be NULL. If fColorCount is not null, it will be
+         *  set to 0.
+         *
+         *  The default is NULL for both pointers.
+         */
+        SkPMColor* fColorPtr;
+        int*       fColorCount;
+
+        /**
          *  The client may provide an integer downscale factor for the decode.
          *  The codec may implement this downscaling by sampling or another
          *  method if it is more efficient.
@@ -206,6 +224,14 @@ public:
      *         to scale or subset. If the codec cannot perform this
      *         scaling or subsetting, it will return an error code.
      *
+     *  If info is kIndex8_SkColorType, then the caller must provide storage for up to 256
+     *  SkPMColor values in options->fColorPtr. On success the codec must copy N colors into
+     *  that storage, (where N is the logical number of table entries) and set
+     *  options->fColorCount to N.
+     *
+     *  If info is not kIndex8_SkColorType, options->fColorPtr and options->fColorCount may
+     *  be nullptr.
+     *
      *  The AndroidOptions object is also used to specify any requested scaling or subsetting
      *  using options->fSampleSize and options->fSubset. If NULL, the defaults (as specified above
      *  for AndroidOptions) are used.
@@ -221,7 +247,10 @@ public:
 
     /**
      *  Simplified version of getAndroidPixels() where we supply the default AndroidOptions as
-     *  specified above for AndroidOptions. It will not perform any scaling or subsetting.
+     *  specified above for AndroidOptions.
+     *
+     *  This will return an error if the info is kIndex_8_SkColorType and also will not perform
+     *  any scaling or subsetting.
      */
     SkCodec::Result getAndroidPixels(const SkImageInfo& info, void* pixels, size_t rowBytes);
 
diff --git a/include/codec/SkCodec.h b/include/codec/SkCodec.h
index b78ec69c74..2043d230b1 100644
--- a/include/codec/SkCodec.h
+++ b/include/codec/SkCodec.h
@@ -338,19 +338,26 @@ public:
      *         reported by the codec, the color space transformation is
      *         a no-op.
      *
+     *  If info is kIndex8_SkColorType, then the caller must provide storage for up to 256
+     *  SkPMColor values in ctable. On success the generator must copy N colors into that storage,
+     *  (where N is the logical number of table entries) and set ctableCount to N.
+     *
+     *  If info is not kIndex8_SkColorType, then the last two parameters may be NULL. If ctableCount
+     *  is not null, it will be set to 0.
+     *
      *  If a scanline decode is in progress, scanline mode will end, requiring the client to call
      *  startScanlineDecode() in order to return to decoding scanlines.
      *
      *  @return Result kSuccess, or another value explaining the type of failure.
      */
-    Result getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, const Options*);
+    Result getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, const Options*,
+                     SkPMColor ctable[], int* ctableCount);
 
     /**
-     *  Simplified version of getPixels() that uses the default Options.
+     *  Simplified version of getPixels() that asserts that info is NOT kIndex8_SkColorType and
+     *  uses the default Options.
      */
-    Result getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes) {
-        return this->getPixels(info, pixels, rowBytes, nullptr);
-    }
+    Result getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes);
 
     /**
      *  If decoding to YUV is supported, this returns true.  Otherwise, this
@@ -403,13 +410,25 @@ public:
      *      if present, or the full image as described in dstInfo.
      *  @param options Contains decoding options, including if memory is zero
      *      initialized and whether to decode a subset.
+     *  @param ctable A pointer to a color table.  When dstInfo.colorType() is
+     *      kIndex8, this should be non-NULL and have enough storage for 256
+     *      colors.  The color table will be populated after decoding the palette.
+     *  @param ctableCount A pointer to the size of the color table.  When
+     *      dstInfo.colorType() is kIndex8, this should be non-NULL.  It will
+     *      be modified to the true size of the color table (<= 256) after
+     *      decoding the palette.
      *  @return Enum representing success or reason for failure.
      */
     Result startIncrementalDecode(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
-            const Options*);
+            const Options*, SkPMColor* ctable, int* ctableCount);
+
+    Result startIncrementalDecode(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
+            const Options* options) {
+        return this->startIncrementalDecode(dstInfo, dst, rowBytes, options, nullptr, nullptr);
+    }
 
     Result startIncrementalDecode(const SkImageInfo& dstInfo, void* dst, size_t rowBytes) {
-        return this->startIncrementalDecode(dstInfo, dst, rowBytes, nullptr);
+        return this->startIncrementalDecode(dstInfo, dst, rowBytes, nullptr, nullptr, nullptr);
     }
 
     /**
@@ -460,16 +479,23 @@ public:
      *      those of getInfo, this implies a scale.
      *  @param options Contains decoding options, including if memory is zero
      *      initialized.
+     *  @param ctable A pointer to a color table.  When dstInfo.colorType() is
+     *      kIndex8, this should be non-NULL and have enough storage for 256
+     *      colors.  The color table will be populated after decoding the palette.
+     *  @param ctableCount A pointer to the size of the color table.  When
+     *      dstInfo.colorType() is kIndex8, this should be non-NULL.  It will
+     *      be modified to the true size of the color table (<= 256) after
+     *      decoding the palette.
      *  @return Enum representing success or reason for failure.
      */
-    Result startScanlineDecode(const SkImageInfo& dstInfo, const Options* options);
+    Result startScanlineDecode(const SkImageInfo& dstInfo, const Options* options,
+            SkPMColor ctable[], int* ctableCount);
 
     /**
-     *  Simplified version of startScanlineDecode() that uses the default Options.
+     *  Simplified version of startScanlineDecode() that asserts that info is NOT
+     *  kIndex8_SkColorType and uses the default Options.
      */
-    Result startScanlineDecode(const SkImageInfo& dstInfo) {
-        return this->startScanlineDecode(dstInfo, nullptr);
-    }
+    Result startScanlineDecode(const SkImageInfo& dstInfo);
 
     /**
      *  Write the next countLines scanlines into dst.
@@ -713,6 +739,7 @@ protected:
      */
     virtual Result onGetPixels(const SkImageInfo& info,
                                void* pixels, size_t rowBytes, const Options&,
+                               SkPMColor ctable[], int* ctableCount,
                                int* rowsDecoded) = 0;
 
     virtual bool onQueryYUV8(SkYUVSizeInfo*, SkYUVColorSpace*) const {
@@ -774,6 +801,7 @@ protected:
      * kN32_SkColorType: Transparent or Black, depending on the src alpha type
      * kRGB_565_SkColorType: Black
      * kGray_8_SkColorType: Black
+     * kIndex_8_SkColorType: First color in color table
      */
     virtual uint64_t onGetFillValue(const SkImageInfo& dstInfo) const;
 
@@ -873,12 +901,12 @@ private:
 
     // Methods for scanline decoding.
     virtual Result onStartScanlineDecode(const SkImageInfo& /*dstInfo*/,
-            const Options& /*options*/) {
+            const Options& /*options*/, SkPMColor* /*ctable*/, int* /*ctableCount*/) {
         return kUnimplemented;
     }
 
     virtual Result onStartIncrementalDecode(const SkImageInfo& /*dstInfo*/, void*, size_t,
-            const Options&) {
+            const Options&, SkPMColor*, int*) {
         return kUnimplemented;
     }
 
diff --git a/include/codec/SkEncodedInfo.h b/include/codec/SkEncodedInfo.h
index 3b1ce48713..eb8c147a3b 100644
--- a/include/codec/SkEncodedInfo.h
+++ b/include/codec/SkEncodedInfo.h
@@ -130,7 +130,7 @@ public:
             case kPalette_Color: {
                 SkAlphaType alphaType = (kOpaque_Alpha == fAlpha) ? kOpaque_SkAlphaType :
                         kUnpremul_SkAlphaType;
-                return SkImageInfo::Make(width, height, kN32_SkColorType,
+                return SkImageInfo::Make(width, height, kIndex_8_SkColorType,
                                          alphaType, colorSpace);
             }
             case kRGB_Color: