Blink: Refactor ImageDecoder::DecodeToYUV API to be analagous to Decode.

Changes return type of DecodeToYUV from bool to void and passes errors
through Failed().

Bug: 900589
Change-Id: If9e9b81d1516eeb7504f79e67a9a77cad4c36151
Reviewed-on: https://chromium-review.googlesource.com/c/1477814
Commit-Queue: Madeleine Barowsky <mbarowsky@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Reviewed-by: Khushal <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633772}

third_party/blink/renderer/platform/graphics/image_frame_generator.cc

@@ -178,9 +178,8 @@ bool ImageFrameGenerator::DecodeToYUV(SegmentReader* data,
       std::make_unique<ImagePlanes>(planes, row_bytes);
   decoder->SetImagePlanes(std::move(image_planes));
 
-  DCHECK(decoder->CanDecodeToYUV());
-
-  if (decoder->DecodeToYUV()) {
+  decoder->DecodeToYUV();
+  if (!decoder->Failed()) {
     // TODO(crbug.com/910276): Set this properly for alpha support.
     SetHasAlpha(index, false);
     return true;

third_party/blink/renderer/platform/image-decoders/image_decoder.h

@@ -325,7 +325,9 @@ class PLATFORM_EXPORT ImageDecoder {
   }
 
   virtual bool CanDecodeToYUV() { return false; }
-  virtual bool DecodeToYUV() { return false; }
+  // Should only be called if CanDecodeToYuv() returns true, in which case
+  // the subclass of ImageDecoder must override this method.
+  virtual void DecodeToYUV() { NOTREACHED(); }
   virtual void SetImagePlanes(std::unique_ptr<ImagePlanes>) {}
 
  protected:

third_party/blink/renderer/platform/image-decoders/jpeg/jpeg_image_decoder.cc

@@ -922,28 +922,31 @@ bool JPEGImageDecoder::ShouldGenerateAllSizes() const {
 }
 
 bool JPEGImageDecoder::CanDecodeToYUV() {
-  // TODO(crbug.com/919627): Re-enable the code below once JPEG YUV decoding is
-  // finished.
+  // TODO(crbug.com/919627): Right now |decode_to_yuv_for_testing_| is false by
+  // default and is only set true for unit tests. Remove it once
+  // JPEG YUV decoding is finished and YUV decoding doesn't need to be disabled
+  // outside of tests.
+  //
   // Returning false here is a bit deceptive because the JPEG decoder does
   // support YUV. But the rest of the infrastructure at levels above the decoder
   // is not quite there yet to handle the resulting JPEG YUV data,
   // so for now we disable that path.
-  return false;
+  //
   // Calling IsSizeAvailable() ensures the reader is created and the output
   // color space is set.
-  // return IsSizeAvailable() && reader_->Info()->out_color_space == JCS_YCbCr;
+  return decode_to_yuv_for_testing_ && IsSizeAvailable() &&
+         reader_->Info()->out_color_space == JCS_YCbCr;
 }
 
-bool JPEGImageDecoder::DecodeToYUV() {
-  if (!HasImagePlanes())
-    return false;
+void JPEGImageDecoder::DecodeToYUV() {
+  DCHECK(HasImagePlanes());
+  DCHECK(CanDecodeToYUV());
 
   {
     TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "Decode Image",
                  "imageType", "JPEG");
     Decode(false);
   }
-  return !Failed();
 }
 
 void JPEGImageDecoder::SetImagePlanes(

third_party/blink/renderer/platform/image-decoders/jpeg/jpeg_image_decoder.h

@@ -47,7 +47,7 @@ class PLATFORM_EXPORT JPEGImageDecoder final : public ImageDecoder {
   IntSize DecodedYUVSize(int component) const override;
   size_t DecodedYUVWidthBytes(int component) const override;
   bool CanDecodeToYUV() override;
-  bool DecodeToYUV() override;
+  void DecodeToYUV() override;
   void SetImagePlanes(std::unique_ptr<ImagePlanes>) override;
   std::vector<SkISize> GetSupportedDecodeSizes() const override;
   bool HasImagePlanes() const { return image_planes_.get(); }
@@ -63,6 +63,9 @@ class PLATFORM_EXPORT JPEGImageDecoder final : public ImageDecoder {
   void SetDecodedSize(unsigned width, unsigned height);
 
   void SetSupportedDecodeSizes(std::vector<SkISize> sizes);
+  void SetDecodeToYuvForTesting(bool decode_to_yuv) {
+    decode_to_yuv_for_testing_ = decode_to_yuv;
+  }
 
  private:
   // ImageDecoder:
@@ -78,6 +81,7 @@ class PLATFORM_EXPORT JPEGImageDecoder final : public ImageDecoder {
   std::unique_ptr<ImagePlanes> image_planes_;
   IntSize decoded_size_;
   std::vector<SkISize> supported_decode_sizes_;
+  bool decode_to_yuv_for_testing_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(JPEGImageDecoder);
 };

third_party/blink/renderer/platform/image-decoders/jpeg/jpeg_image_decoder_test.cc

@@ -51,7 +51,7 @@ static const size_t kLargeEnoughSize = 1000 * 1000;
 
 namespace {
 
-std::unique_ptr<ImageDecoder> CreateJPEGDecoder(size_t max_decoded_bytes) {
+std::unique_ptr<JPEGImageDecoder> CreateJPEGDecoder(size_t max_decoded_bytes) {
   return std::make_unique<JPEGImageDecoder>(
       ImageDecoder::kAlphaNotPremultiplied, ColorBehavior::TransformToSRGB(),
       max_decoded_bytes);
@@ -89,8 +89,10 @@ void ReadYUV(size_t max_decoded_bytes,
   scoped_refptr<SharedBuffer> data = ReadFile(image_file_path);
   ASSERT_TRUE(data);
 
-  std::unique_ptr<ImageDecoder> decoder = CreateJPEGDecoder(max_decoded_bytes);
+  std::unique_ptr<JPEGImageDecoder> decoder =
+      CreateJPEGDecoder(max_decoded_bytes);
   decoder->SetData(data.get(), true);
+  decoder->SetDecodeToYuvForTesting(true);
 
   // Setting a dummy ImagePlanes object signals to the decoder that we want to
   // do YUV decoding.
@@ -134,7 +136,8 @@ void ReadYUV(size_t max_decoded_bytes,
       std::make_unique<ImagePlanes>(planes, row_bytes);
   decoder->SetImagePlanes(std::move(image_planes));
 
-  ASSERT_TRUE(decoder->DecodeToYUV());
+  decoder->DecodeToYUV();
+  ASSERT_TRUE(!decoder->Failed());
 }
 
 // Tests failure on a too big image.
@@ -262,8 +265,9 @@ TEST(JPEGImageDecoderTest, yuv) {
   scoped_refptr<SharedBuffer> data = ReadFile(jpeg_file);
   ASSERT_TRUE(data);
 
-  std::unique_ptr<ImageDecoder> decoder = CreateJPEGDecoder(230 * 230 * 4);
+  std::unique_ptr<JPEGImageDecoder> decoder = CreateJPEGDecoder(230 * 230 * 4);
   decoder->SetData(data.get(), true);
+  decoder->SetDecodeToYuvForTesting(true);
 
   std::unique_ptr<ImagePlanes> image_planes = std::make_unique<ImagePlanes>();
   decoder->SetImagePlanes(std::move(image_planes));