Allow CopyFromBackingStore to fallback to copying from the renderer side if the accelerated surface…

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 2c9d0d2cb200ad954da2e802efaa9533c3f01721..1495a397899f6062fd849f785eec6e2726eb73e2 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -391,6 +391,7 @@ bool RenderWidgetHostImpl::OnMessageReceived(const IPC::Message &msg) {
     IPC_MESSAGE_HANDLER(ViewHostMsg_WindowlessPluginDummyWindowDestroyed,
                         OnWindowlessPluginDummyWindowDestroyed)
 #endif
+    IPC_MESSAGE_HANDLER(ViewHostMsg_Snapshot, OnSnapshot)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
 
@@ -598,6 +599,42 @@ void RenderWidgetHostImpl::CopyFromBackingStore(
   callback.Run(result, output.GetBitmap());
 }
 
+void RenderWidgetHostImpl::GetSnapshotFromRenderer(
+    const gfx::Rect& src_subrect,
+    const gfx::Size& dst_size,
+    const base::Callback<void(bool, const SkBitmap&)>& callback) {
+  TRACE_EVENT0("browser", "RenderWidgetHostImpl::GetSnapshotFromRenderer");
+  pending_snapshots_.push(std::make_pair(dst_size, callback));
+  Send(new ViewMsg_Snapshot(routing_id_, src_subrect));
+}
+
+void RenderWidgetHostImpl::OnSnapshot(bool success,
+                                      const SkBitmap& bitmap) {
+  if (pending_snapshots_.size() == 0) {
+    LOG(ERROR) << "RenderWidgetHostImpl::OnSnapshot: "
+                  "Received a snapshot that was not requested.";
+    return;
+  }
+
+  PendingSnapshotInfo snapshot_info = pending_snapshots_.front();
+  pending_snapshots_.pop();
+
+  const gfx::Size& dst_size = snapshot_info.first;
+  const base::Callback<void(bool, const SkBitmap&)>& callback =
+      snapshot_info.second;
+
+  if (!success) {
+    callback.Run(success, SkBitmap());
+    return;
+  }
+
+  SkBitmap resized = skia::ImageOperations::Resize(
+      bitmap, skia::ImageOperations::RESIZE_GOOD, dst_size.width(),
+      dst_size.height());
+
+  callback.Run(success, resized);
+}
+
 #if defined(TOOLKIT_GTK)
 bool RenderWidgetHostImpl::CopyFromBackingStoreToGtkWindow(
     const gfx::Rect& dest_rect, GdkWindow* target) {