Remove redundant codepath for webgl api blocking

content/common/frame_messages.h

 // Copyright 2013 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 interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 1049 matching lines @@
                             bool /* cookies_enabled */)
 
 // Sent by the renderer process to check whether client 3D APIs
 // (Pepper 3D, WebGL) are explicitly blocked.
 IPC_SYNC_MESSAGE_CONTROL3_1(FrameHostMsg_Are3DAPIsBlocked,
                             int /* render_frame_id */,
                             GURL /* top_origin_url */,
                             content::ThreeDAPIType /* requester */,
                             bool /* blocked */)
 
-// Sent by the renderer process to indicate that a context was lost by
-// client 3D content (Pepper 3D, WebGL) running on the page at the
-// given URL.
-IPC_MESSAGE_CONTROL3(FrameHostMsg_DidLose3DContext,
-                     GURL /* top_origin_url */,
-                     content::ThreeDAPIType /* context_type */,
-                     int /* arb_robustness_status_code */)
-
 #if defined(ENABLE_PLUGINS)
 // Notification sent from a renderer to the browser that a Pepper plugin
 // instance is created in the DOM.
 IPC_MESSAGE_ROUTED0(FrameHostMsg_PepperInstanceCreated)
 
 // Notification sent from a renderer to the browser that a Pepper plugin
 // instance is deleted from the DOM.
 IPC_MESSAGE_ROUTED0(FrameHostMsg_PepperInstanceDeleted)
 
 // Sent to the browser when the renderer detects it is blocked on a pepper
@@ skipping 358 matching lines @@
 IPC_MESSAGE_ROUTED3(FrameHostMsg_FindMatchRects_Reply,
                     int /* version */,
                     std::vector<gfx::RectF> /* rects */,
                     gfx::RectF /* active_rect */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent FrameMsg, then ifdefs for platform specific FrameMsg, then
 // platform independent FrameHostMsg, then ifdefs for platform specific
 // FrameHostMsg.