[blink] Request compositing update when canvas hibernates/wakes up.

third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp

 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
@@ skipping 576 matching lines @@
   surface->Canvas()->drawImage(std::move(image), 0, 0);
 
   surface->SetImageBuffer(this);
   if (client_)
     client_->RestoreCanvasMatrixClipStack(surface->Canvas());
   surface_ = std::move(surface);
 
   UpdateGPUMemoryUsage();
 }
 
+void ImageBuffer::SetNeedsCompositingUpdate() {
+  if (client_)
+    client_->SetNeedsCompositingUpdate();
+}
+
 bool ImageDataBuffer::EncodeImage(const String& mime_type,
                                   const double& quality,
                                   Vector<unsigned char>* encoded_image) const {
   if (mime_type == "image/jpeg") {
     if (!JPEGImageEncoder::Encode(*this, quality, encoded_image))
       return false;
   } else if (mime_type == "image/webp") {
     int compression_quality = WEBPImageEncoder::kDefaultCompressionQuality;
     if (quality >= 0.0 && quality <= 1.0)
       compression_quality = static_cast<int>(quality * 100 + 0.5);
@@ skipping 13 matching lines @@
   DCHECK(MIMETypeRegistry::IsSupportedImageMIMETypeForEncoding(mime_type));
 
   Vector<unsigned char> result;
   if (!EncodeImage(mime_type, quality, &result))
     return "data:,";
 
   return "data:" + mime_type + ";base64," + Base64Encode(result);
 }
 
 }  // namespace blink