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

content/common/view_messages.h

Index: content/common/view_messages.h
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index c186f21647eee0f7de0e92473e89e313746427c5..a498b41bbf57573fabe3a017cc411533e7b67b8f 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -1386,6 +1386,14 @@ IPC_MESSAGE_ROUTED1(ViewMsg_SelectPopupMenuItem,
 IPC_MESSAGE_ROUTED1(ViewMsg_SwapCompositorFrameAck,
                     cc::CompositorFrameAck /* ack */)
 
+// Sent from the browser to ask the renderer for a snapshot of the current view.

[jamesr, 2013/03/18 01:32:19]

This IPC pair already exists:

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/common/rend...

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/common/rend...

Please don't add duplicate code (or in this case, very nearly duplicate code)

[justinlin, 2013/03/18 03:21:14]

Right, but we would like to use it from content/, hence the goal of this CL is
to move that functionality into content/, and then delete SnapshotTabHelper in a
separate CL (patch #1 did the delete, but I would like to do it separately).

+// The renderer replies with whether the snapshot succeeded and the SkBitmap.
+IPC_MESSAGE_ROUTED1(ViewMsg_Snapshot,
+                    gfx::Rect /* src_subrect */)
+IPC_MESSAGE_ROUTED2(ViewHostMsg_Snapshot,
+                    bool, /* success */
+                    SkBitmap /* bitmap */)
+
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.