Make command-zero reset page scale in addition to zoom level

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/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/strings/string16.h"
@@ skipping 671 matching lines @@
 // Tells the renderer to perform the given action on the plugin located at
 // the given point.
 IPC_MESSAGE_ROUTED2(ViewMsg_PluginActionAt,
                     gfx::Point, /* location */
                     blink::WebPluginAction)
 
 // Posts a message from a frame in another process to the current renderer.
 IPC_MESSAGE_ROUTED1(ViewMsg_PostMessageEvent,
                     ViewMsg_PostMessage_Params)
 
+// Resets the page scale for the current main frame to the default page scale.
+IPC_MESSAGE_ROUTED0(ViewMsg_ResetPageScale)
+
 // Change the zoom level for the current main frame.  If the level actually
 // changes, a ViewHostMsg_DidZoomURL message will be sent back to the browser
 // telling it what url got zoomed and what its current zoom level is.
 IPC_MESSAGE_ROUTED1(ViewMsg_Zoom,
                     content::PageZoom /* function */)
 
 // Set the zoom level for a particular url that the renderer is in the
 // process of loading.  This will be stored, to be used if the load commits
 // and ignored otherwise.
 IPC_MESSAGE_ROUTED2(ViewMsg_SetZoomLevelForLoadingURL,
@@ skipping 952 matching lines @@
 // cached by the OS. Please see RenderMessageFilter::OnPreCacheFontCharacters
 // for details.
 IPC_SYNC_MESSAGE_CONTROL2_0(ViewHostMsg_PreCacheFontCharacters,
                             LOGFONT /* font_data */,
                             base::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.