Allow changing top controls height

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 402 matching lines @@
   IPC_STRUCT_MEMBER(int, flags)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(ViewMsg_Resize_Params)
   // Information about the screen (dpi, depth, etc..).
   IPC_STRUCT_MEMBER(blink::WebScreenInfo, screen_info)
   // The size of the renderer.
   IPC_STRUCT_MEMBER(gfx::Size, new_size)
   // The size of the view's backing surface in non-DPI-adjusted pixels.
   IPC_STRUCT_MEMBER(gfx::Size, physical_backing_size)
-  // The amount that the viewport size given to Blink was shrunk by the URL-bar
-  // (always 0 on platforms where URL-bar hiding isn't supported).
-  IPC_STRUCT_MEMBER(float, top_controls_layout_height)
+  // Whether or not Blink's viewport size should be shrunk by the height of the
+  // URL-bar (always false on platforms where URL-bar hiding isn't supported).
+  IPC_STRUCT_MEMBER(bool, top_controls_shrink_blink_size)
+  // The height of the top controls (always 0 on platforms where URL-bar hiding
+  // isn't supported).
+  IPC_STRUCT_MEMBER(float, top_controls_height)
   // The size of the visible viewport, which may be smaller than the view if the
   // view is partially occluded (e.g. by a virtual keyboard).  The size is in
   // DPI-adjusted pixels.
   IPC_STRUCT_MEMBER(gfx::Size, visible_viewport_size)
   // The resizer rect.
   IPC_STRUCT_MEMBER(gfx::Rect, resizer_rect)
   // Indicates whether a page is fullscreen or not.
   IPC_STRUCT_MEMBER(bool, is_fullscreen)
 IPC_STRUCT_END()
 
@@ skipping 1227 matching lines @@
 // Since the browser keeps handles to the allocated transport DIBs, this
 // message is sent to tell the browser that it may release them when the
 // renderer is finished with them.
 IPC_MESSAGE_CONTROL1(ViewHostMsg_FreeTransportDIB,
                      TransportDIB::Id /* DIB id */)
 #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.