Implemented GetWindowSnapshot on RenderViewImpl

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 5956f0d33a982ecee573dee55e36d1420a63752d..4441248358bf82ff347e64bfd118b72d3e22b013 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -1446,6 +1446,12 @@ IPC_MESSAGE_ROUTED1(ViewMsg_SelectPopupMenuItem,
 IPC_MESSAGE_ROUTED1(ViewMsg_ReleaseDisambiguationPopupDIB,
                     TransportDIB::Handle /* DIB handle */)
 
+// Notifies the renderer that a snapshot has been retrieved.
+IPC_MESSAGE_ROUTED3(ViewMsg_WindowSnapshotCompleted,
+                    int /* snapshot_id */,
+                    gfx::Size /* size */,
+                    std::vector<unsigned char> /* png */)
+
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.
 
@@ -1945,6 +1951,10 @@ IPC_MESSAGE_ROUTED3(ViewHostMsg_WebUISend,
                     std::string  /* message */,
                     base::ListValue /* args */)
 
+// Requests a snapshot of the given window.
+IPC_MESSAGE_ROUTED1(ViewHostMsg_GetWindowSnapshot,
+                    int /* snapshot_id */)
+
 // A renderer sends this to the browser process when it wants to create a ppapi
 // plugin.  The browser will create the plugin process if necessary, and will
 // return a handle to the channel on success.