Revert of Remove SK_SUPPORT_LEGACY_DEEPFLATTENING. (patchset #1 id:1 of https://codereview.chromium.org/769953002/)

Reason for revert:
Breaks canary builds.  Will reland after the Chromium change lands.

Original issue's description:
> Remove SK_SUPPORT_LEGACY_DEEPFLATTENING.
>
> This was needed for pictures before v33, and we're now requiring v35+.
>
> Will follow up with the same for skia/ext/pixel_ref_utils_unittest.cc
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/52c293547b973f7fb5de3c83f5062b07d759ab88

TBR=reed@google.com,mtklein@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/768183002

1 files changed, 50 insertions, 0 deletions

diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index e70be04697..d7b51440b3 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -199,6 +199,56 @@ SkGradientShaderBase::SkGradientShaderBase(const Descriptor& desc)
     this->initCommon();
 }
 
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
+static SkShader::TileMode unpack_mode(uint32_t packed) {
+    return (SkShader::TileMode)(packed & 0xF);
+}
+
+static uint32_t unpack_flags(uint32_t packed) {
+    return packed >> 4;
+}
+
+SkGradientShaderBase::SkGradientShaderBase(SkReadBuffer& buffer) : INHERITED(buffer) {
+    int colorCount = fColorCount = buffer.getArrayCount();
+    if (colorCount > kColorStorageCount) {
+        size_t allocSize = (sizeof(SkColor) + sizeof(SkScalar) + sizeof(Rec)) * colorCount;
+        if (buffer.validateAvailable(allocSize)) {
+            fOrigColors = reinterpret_cast<SkColor*>(sk_malloc_throw(allocSize));
+        } else {
+            fOrigColors =  NULL;
+            colorCount = fColorCount = 0;
+        }
+    } else {
+        fOrigColors = fStorage;
+    }
+    buffer.readColorArray(fOrigColors, colorCount);
+
+    fOrigPos = (SkScalar*)(fOrigColors + colorCount);
+
+    {
+        uint32_t packed = buffer.readUInt();
+        fGradFlags = SkToU8(unpack_flags(packed));
+        fTileMode = unpack_mode(packed);
+    }
+    fTileProc = gTileProcs[fTileMode];
+    fRecs = (Rec*)(fOrigPos + colorCount);
+    if (colorCount > 2) {
+        Rec* recs = fRecs;
+        recs[0].fPos = 0;
+        fOrigPos[0] = 0;
+        for (int i = 1; i < colorCount; i++) {
+            recs[i].fPos = buffer.readInt();
+            recs[i].fScale = buffer.readUInt();
+            fOrigPos[i] = SkFixedToScalar(recs[i].fPos);
+        }
+    } else {
+        fOrigPos = NULL;
+    }
+    buffer.readMatrix(&fPtsToUnit);
+    this->initCommon();
+}
+#endif
+
 SkGradientShaderBase::~SkGradientShaderBase() {
     if (fOrigColors != fStorage) {
         sk_free(fOrigColors);