Use GLHelper support to validate format before processing texture.

content/browser/compositor/delegated_frame_host.cc

Index: content/browser/compositor/delegated_frame_host.cc
diff --git a/content/browser/compositor/delegated_frame_host.cc b/content/browser/compositor/delegated_frame_host.cc
index e09c38ebc6589ccc1ec5a9ef82e6bc7703ce974a..91a2d07acf3bc4c7a2dbce62bbb1046b1afd812f 100644
--- a/content/browser/compositor/delegated_frame_host.cc
+++ b/content/browser/compositor/delegated_frame_host.cc
@@ -618,12 +618,20 @@ void DelegatedFrameHost::PrepareTextureCopyOutputResult(
     ReadbackRequestCallback& callback,
     scoped_ptr<cc::CopyOutputResult> result) {
   DCHECK(result->HasTexture());

[danakj, 2015/01/08 05:56:31]

Nit: blank line between dcheck and code

[sivag, 2015/01/08 11:03:31]

Done.

+  ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
+  GLHelper* gl_helper = factory->GetGLHelper();
+  if (!gl_helper) {
+    callback.Run(SkBitmap(), content::READBACK_FAILED);
+    return;
+  }
+  if (!gl_helper->IsReadbackConfigSupported(color_type)) {
+    callback.Run(SkBitmap(), content::READBACK_FORMAT_NOT_SUPPORTED);
+    return;
+  }
+
   base::ScopedClosureRunner scoped_callback_runner(

[danakj, 2015/01/08 05:56:31]

Maybe move this to the top of the function, and just reset the scoped runner
when calling with format error?

[sivag, 2015/01/08 11:03:31]

Done.

       base::Bind(callback, SkBitmap(), content::READBACK_FAILED));
 
-  // TODO(sikugu): We should be able to validate the format here using
-  // GLHelper::IsReadbackConfigSupported before we processs the result.
-  // See crbug.com/415682.
   scoped_ptr<SkBitmap> bitmap(new SkBitmap);
   if (!bitmap->tryAllocPixels(SkImageInfo::Make(dst_size_in_pixel.width(),
                                                 dst_size_in_pixel.height(),
@@ -631,11 +639,6 @@ void DelegatedFrameHost::PrepareTextureCopyOutputResult(
                                                 kOpaque_SkAlphaType)))
     return;
 
-  ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
-  GLHelper* gl_helper = factory->GetGLHelper();
-  if (!gl_helper)
-    return;
-
   scoped_ptr<SkAutoLockPixels> bitmap_pixels_lock(
       new SkAutoLockPixels(*bitmap));
   uint8* pixels = static_cast<uint8*>(bitmap->getPixels());