Reland "Remove support for decoding to kIndex_8"

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>

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

Bug: skia:6828
Change-Id: I36ff5a11c529d29e8adc95f43b8edc6fd1dbf5b8
Reviewed-on: https://skia-review.googlesource.com/22320
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>

2 files changed, 2 insertions, 8 deletions

diff --git a/third_party/gif/SkGifImageReader.cpp b/third_party/gif/SkGifImageReader.cpp
index 76f3edcef0..e76028dac9 100644
--- a/third_party/gif/SkGifImageReader.cpp
+++ b/third_party/gif/SkGifImageReader.cpp
@@ -762,13 +762,11 @@ bool SkGifImageReader::parse(SkGifImageReader::SkGIFParseQuery query)
                         isLocalColormapDefined, numColors))
                 {
                     m_firstFrameHasAlpha = true;
-                    m_firstFrameSupportsIndex8 = true;
                 } else {
                     const bool frameIsSubset = xOffset > 0 || yOffset > 0
                             || width < fScreenWidth
                             || height < fScreenHeight;
                     m_firstFrameHasAlpha = frameIsSubset;
-                    m_firstFrameSupportsIndex8 = !frameIsSubset;
                 }
             }
 
diff --git a/third_party/gif/SkGifImageReader.h b/third_party/gif/SkGifImageReader.h
index f105a1de87..49655c23df 100644
--- a/third_party/gif/SkGifImageReader.h
+++ b/third_party/gif/SkGifImageReader.h
@@ -289,7 +289,6 @@ public:
         , m_streamBuffer(stream)
         , m_parseCompleted(false)
         , m_firstFrameHasAlpha(false)
-        , m_firstFrameSupportsIndex8(false)
     {
     }
 
@@ -367,8 +366,6 @@ public:
 
     bool firstFrameHasAlpha() const { return m_firstFrameHasAlpha; }
 
-    bool firstFrameSupportsIndex8() const { return m_firstFrameSupportsIndex8; }
-
     // Helper function that returns whether an SkGIFFrameContext has transparency.
     // This method is sometimes called before creating one/parsing its color map,
     // so it cannot rely on SkGIFFrameContext::transparentPixel or ::localColorMap().
@@ -410,10 +407,9 @@ private:
     SkStreamBuffer m_streamBuffer;
     bool m_parseCompleted;
 
-    // These values can be computed before we create a SkGIFFrameContext, so we
-    // store them here instead of on m_frames[0].
+    // This value can be computed before we create a SkGIFFrameContext, so we
+    // store it here instead of on m_frames[0].
     bool m_firstFrameHasAlpha;
-    bool m_firstFrameSupportsIndex8;
 };
 
 #endif