Consolidate RenderWidgetHost::CopyFromBackingStore and RenderWidgetHost::AsyncCopyFromBackingStore.

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index 83f76a8ac4fa5dd6cc19115037892f0e686d24de..6800dd46619e589930f429ccd383080ace96c71e 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -7,6 +7,7 @@
 #include <QuartzCore/QuartzCore.h>
 
 #include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/mac/closure_blocks_leopard_compat.h"
@@ -789,27 +790,22 @@ BackingStore* RenderWidgetHostViewMac::AllocBackingStore(
   return new BackingStoreMac(render_widget_host_, size);
 }
 
-bool RenderWidgetHostViewMac::CopyFromCompositingSurface(
-      const gfx::Size& size,
-      skia::PlatformCanvas* output) {
+void RenderWidgetHostViewMac::CopyFromCompositingSurface(
+    const gfx::Size& size,
+    skia::PlatformCanvas* output,
+    base::Callback<void(bool)> callback) {
+  base::ScopedClosureRunner scoped_callback_runner(base::Bind(callback, false));
   if (!compositing_iosurface_.get() ||
       !compositing_iosurface_->HasIOSurface())
-    return false;
+    return;
 
   if (!output->initialize(size.width(), size.height(), true))
-    return false;
+    return;
 
-  return compositing_iosurface_->CopyTo(
+  const bool result = compositing_iosurface_->CopyTo(
       size, output->getTopDevice()->accessBitmap(true).getPixels());
-}
-
-void RenderWidgetHostViewMac::AsyncCopyFromCompositingSurface(
-    const gfx::Size& size,
-    skia::PlatformCanvas* output,
-    base::Callback<void(bool)> callback) {
-  // TODO(mazda): Implement this.
-  NOTIMPLEMENTED();
-  callback.Run(false);
+  scoped_callback_runner.Release();
+  callback.Run(result);
 }
 
 // Sets whether or not to accept first responder status.