Query the preferred readback config in CopyFromBackingStore

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index c715fcac51e35b0b9e381cd686dd1453f7b7ecc8..90b16d49f33c00f57c2bc614b14e1f11b394fe2d 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -33,6 +33,7 @@
 #include "content/browser/renderer_host/backing_store.h"
 #include "content/browser/renderer_host/backing_store_manager.h"
 #include "content/browser/renderer_host/dip_util.h"
+#include "content/browser/renderer_host/image_transport_factory_android.h"
 #include "content/browser/renderer_host/input/input_router_impl.h"
 #include "content/browser/renderer_host/input/synthetic_gesture.h"
 #include "content/browser/renderer_host/input/synthetic_gesture_controller.h"
@@ -45,6 +46,7 @@
 #include "content/browser/renderer_host/render_widget_host_delegate.h"
 #include "content/common/accessibility_messages.h"
 #include "content/common/content_constants_internal.h"
+#include "content/common/gpu/client/gl_helper.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/common/input_messages.h"
 #include "content/common/view_messages.h"
@@ -724,10 +726,17 @@ void RenderWidgetHostImpl::CopyFromBackingStore(
         "RenderWidgetHostImpl::CopyFromBackingStore::FromCompositingSurface");
     gfx::Rect accelerated_copy_rect = src_subrect.IsEmpty() ?
         gfx::Rect(view_->GetViewBounds().size()) : src_subrect;
+    ImageTransportFactoryAndroid* factory =
+        ImageTransportFactoryAndroid::GetInstance();
+    GLHelper* gl_helper = factory->GetGLHelper();
+    SkBitmap::Config preffered_format = SkBitmap::kARGB_8888_Config;
+    DCHECK(gl_helper);
+    if (gl_helper)
+      preffered_format = gl_helper->PreferredReadbackFormat();

[piman, 2014/03/06 22:01:52]

This code is out-of-place.
1- Obviously we can't access Android things on non-Android.
2- Some platforms (e.g. mac) don't have a GLHelper, and a GLHelper is not
involved in the readback

Maybe what you want is ask view_ what is the preferred format, and these can
delegate to their GLHelper if appropriate?

[sivag, 2014/03/10 15:48:18]

Done.

     view_->CopyFromCompositingSurface(accelerated_copy_rect,
                                       accelerated_dst_size,
                                       callback,
-                                      SkBitmap::kARGB_8888_Config);
+                                      preffered_format);
     return;
   }