Check StaticBitmapImage has changed from Mailbox to Skia in OffscreenCanvas commit

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/graphics/OffscreenCanvasFrameDispatcherImpl.h"
 
 #include "cc/output/compositor_frame.h"
 #include "cc/quads/texture_draw_quad.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "platform/CrossThreadFunctional.h"
@@ skipping 382 matching lines @@
 void OffscreenCanvasFrameDispatcherImpl::OnBeginFrame(
     const cc::BeginFrameArgs& beginFrameArgs) {
   DCHECK(client());
   client()->beginFrame();
 }
 
 void OffscreenCanvasFrameDispatcherImpl::ReclaimResources(
     const cc::ReturnedResourceArray& resources) {
   for (const auto& resource : resources) {
     RefPtr<StaticBitmapImage> image = m_cachedImages.at(resource.id);
-    if (image)
-      image->updateSyncToken(resource.sync_token);
+
+    if (image) {
+      if (image->hasMailbox()) {
+        image->updateSyncToken(resource.sync_token);
+      } else if (SharedGpuContext::isValid() && resource.sync_token.HasData()) {
+        // Although image has MailboxTextureHolder at the time when it is
+        // inserted to m_cachedImages, the
+        // OffscreenCanvasPlaceHolder::placeholderFrame() exposes this image to
+        // everyone accessing the placeholder canvas as an image source, some of
+        // which may want to consume the image as a SkImage, thereby converting
+        // the MailTextureHolder to a SkiaTextureHolder. In this case, we
+        // need to wait for the new sync token passed by CompositorFrameSink.
+        SharedGpuContext::gl()->WaitSyncTokenCHROMIUM(
+            resource.sync_token.GetConstData());
+      }
+    }
     reclaimResource(resource.id);
   }
 }
 
 void OffscreenCanvasFrameDispatcherImpl::WillDrawSurface(
     const cc::LocalSurfaceId& localSurfaceId,
     ::gfx::mojom::blink::RectPtr damageRect) {
   // TODO(fsamuel, staraz): Implement this.
 }
 
@@ skipping 22 matching lines @@
 
 void OffscreenCanvasFrameDispatcherImpl::reshape(int width, int height) {
   if (m_width != width || m_height != height) {
     m_width = width;
     m_height = height;
     m_changeSizeForNextCommit = true;
   }
 }
 
 }  // namespace blink