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

content/common/view_messages.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "base/string16.h"
@@ skipping 1368 matching lines @@
 
 // External popup menus.
 IPC_MESSAGE_ROUTED1(ViewMsg_SelectPopupMenuItem,
                     int /* selected index, -1 means no selection */)
 #endif
 
 // Sent by the browser as a reply to ViewHostMsg_SwapCompositorFrame.
 IPC_MESSAGE_ROUTED1(ViewMsg_SwapCompositorFrameAck,
                     cc::CompositorFrameAck /* ack */)
 
+// Sent from the browser to ask the renderer for a snapshot of the current view.
+// 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.
 
 // Sent by the renderer when it is creating a new window.  The browser creates
 // a tab for it and responds with a ViewMsg_CreatingNew_ACK.  If route_id is
 // MSG_ROUTING_NONE, the view couldn't be created.
 IPC_SYNC_MESSAGE_CONTROL1_3(ViewHostMsg_CreateWindow,
                             ViewHostMsg_CreateWindow_Params,
                             int /* route_id */,
                             int32 /* surface_id */,
@@ skipping 1019 matching lines @@
 // cached by the OS. Please see RenderMessageFilter::OnPreCacheFontCharacters
 // for details.
 IPC_SYNC_MESSAGE_CONTROL2_0(ViewHostMsg_PreCacheFontCharacters,
                             LOGFONT /* font_data */,
                             string16 /* characters */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent ViewMsg, then ifdefs for platform specific ViewMsg, then platform
 // independent ViewHostMsg, then ifdefs for platform specific ViewHostMsg.