Stop disabling force_compositing_mode for background RenderViews.

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 475 matching lines @@
   // The route ID of the opener RenderView if we need to set one
   // (MSG_ROUTING_NONE otherwise).
   IPC_STRUCT_MEMBER(int, opener_route_id)
 
   // Whether the RenderView should initially be swapped out.
   IPC_STRUCT_MEMBER(bool, swapped_out)
 
   // Whether the RenderView should initially be hidden.
   IPC_STRUCT_MEMBER(bool, hidden)
 
+  // Whether the RenderView is in the background and will never display.
+  IPC_STRUCT_MEMBER(bool, background)
+
   // The initial page ID to use for this view, which must be larger than any
   // existing navigation that might be loaded in the view.  Page IDs are unique
   // to a view and are only updated by the renderer after this initial value.
   IPC_STRUCT_MEMBER(int32, next_page_id)
 
   // The properties of the screen associated with the view.
   IPC_STRUCT_MEMBER(blink::WebScreenInfo, screen_info)
 
   // The accessibility mode of the renderer.
   IPC_STRUCT_MEMBER(AccessibilityMode, accessibility_mode)
@@ skipping 1386 matching lines @@
 // synchronously (see crbug.com/120597). This IPC message sends the character
 // bounds after every composition change to always have correct bound info.
 IPC_MESSAGE_ROUTED2(ViewHostMsg_ImeCompositionRangeChanged,
                     gfx::Range /* composition range */,
                     std::vector<gfx::Rect> /* character bounds */)
 #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.