blink: Fix frame completion querying for static images.

third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp

 /*
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 164 matching lines @@
   if (!has_histogrammed_color_space_) {
     BitmapImageMetrics::CountImageGammaAndGamut(embedded_color_space_.get());
     has_histogrammed_color_space_ = true;
   }
 
   frame->NotifyBitmapIfPixelsChanged();
   return frame;
 }
 
 bool ImageDecoder::FrameHasAlphaAtIndex(size_t index) const {
-  return !FrameIsCompleteAtIndex(index) ||
+  return index < frame_buffer_cache_.size() &&

[urvang, 2017/05/15 17:33:07]

Shouldn't you call "FrameIsDecodedAtIndex()" now instead?

[Khushal, 2017/05/15 17:55:17]

FrameIsDecodedAtIndex is true only if the decoded data for that frame is cached.
For the cases where the decoder is used just for reading the metadata on the
main thread, this will never be true. From a quick glance, it looks like the
only code that uses it is that exact case in DeferredImageDecoder.

I can just keep the current call FrameIsCompleteAtIndex here to avoid a change
in behaviour?

[urvang, 2017/05/15 18:02:10]

Yes, if keeping the current call still works, you can do this change separately.

[Khushal, 2017/05/15 20:44:48]

Done.

          frame_buffer_cache_[index].HasAlpha();
 }
 
 bool ImageDecoder::FrameIsCompleteAtIndex(size_t index) const {
-  return (index < frame_buffer_cache_.size()) &&
-         (frame_buffer_cache_[index].GetStatus() == ImageFrame::kFrameComplete);
+  // Animated images override this method to return the status based on the data
+  // received for the queried frame.
+  return IsAllDataReceived();

[urvang, 2017/05/15 17:33:07]

I'm curious if you get a warning about "index" being unused here. 

[Khushal, 2017/05/15 17:55:17]

The bots don't seem to be complaining.

[urvang, 2017/05/15 18:02:10]

Acknowledged.

+}
+
+bool ImageDecoder::FrameIsDecodedAtIndex(size_t index) const {
+  return index < frame_buffer_cache_.size() &&
+         frame_buffer_cache_[index].GetStatus() == ImageFrame::kFrameComplete;
 }
 
 size_t ImageDecoder::FrameBytesAtIndex(size_t index) const {
   if (index >= frame_buffer_cache_.size() ||
       frame_buffer_cache_[index].GetStatus() == ImageFrame::kFrameEmpty)
     return 0;
 
   struct ImageSize {
     explicit ImageSize(IntSize size) {
       area = static_cast<uint64_t>(size.Width()) * size.Height();
@@ skipping 375 matching lines @@
     }
 
     // For color spaces without an identifiable gamut, just fall through to
     // sRGB.
   }
 
   return SkColorSpace::MakeSRGB();
 }
 
 }  // namespace blink