Restore SnapshotTabHelper temporarily

chrome/common/render_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.
 
 // Multiply-included file, no traditional include guard.
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 245 matching lines @@
 
 // For WebUI testing, this message stores parameters to do ScriptEvalRequest at
 // a time which is late enough to not be thrown out, and early enough to be
 // before onload events are fired.
 IPC_MESSAGE_ROUTED4(ChromeViewMsg_WebUIJavaScript,
                     string16,  /* frame_xpath */
                     string16,  /* jscript_url */
                     int,  /* ID */
                     bool  /* If true, result is sent back. */)
 
+// Tells the render view to capture a thumbnail image of the page. The
+// render view responds with a ChromeViewHostMsg_Snapshot.
+IPC_MESSAGE_ROUTED0(ChromeViewMsg_CaptureSnapshot)
+
 // Set the content setting rules stored by the renderer.
 IPC_MESSAGE_CONTROL1(ChromeViewMsg_SetContentSettingRules,
                      RendererContentSettingRules /* rules */)
 
 // Tells the render view to load all blocked plugins with the given identifier.
 IPC_MESSAGE_ROUTED1(ChromeViewMsg_LoadBlockedPlugins,
                     std::string /* identifier */)
 
 // Asks the renderer to send back stats on the WebCore cache broken down by
 // resource types.
@@ skipping 268 matching lines @@
 IPC_MESSAGE_ROUTED0(ChromeViewHostMsg_OpenAboutPlugins)
 
 // Tells the browser that there was an error loading a plug-in.
 IPC_MESSAGE_ROUTED1(ChromeViewHostMsg_CouldNotLoadPlugin,
                     base::FilePath /* plugin_path */)
 
 // Tells the browser that we blocked a plug-in because NPAPI is not supported.
 IPC_MESSAGE_ROUTED1(ChromeViewHostMsg_NPAPINotSupported,
                     std::string /* identifer */)
 
+// Send a snapshot of the tab contents to the render host.
+IPC_MESSAGE_ROUTED1(ChromeViewHostMsg_Snapshot,
+                    SkBitmap /* bitmap */)
+
 // A message for an external host.
 IPC_MESSAGE_ROUTED3(ChromeViewHostMsg_ForwardMessageToExternalHost,
                     std::string  /* message */,
                     std::string  /* origin */,
                     std::string  /* target */)
 
 // A renderer sends this to the browser process when it wants to start
 // a new instance of the Native Client process. The browser will launch
 // the process and return an IPC channel handle. This handle will only
 // be valid if the NaCl IPC proxy is enabled.
@@ skipping 166 matching lines @@
 // previous SetCookie message to be processed.
 IPC_SYNC_MESSAGE_ROUTED2_1(ChromeViewHostMsg_GetCookies,
                            GURL /* url */,
                            GURL /* first_party_for_cookies */,
                            std::string /* cookies */)
 
 // Provide the browser process with current renderer framerate.
 IPC_MESSAGE_CONTROL2(ChromeViewHostMsg_FPS,
                      int /* routing id */,
                      float /* frames per second */)