gpu: Fix some context lost marking glitches+leaks and add UMA stats

content/browser/renderer_host/media/video_capture_texture_wrapper.cc

 // Copyright 2015 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.
 
 #include "content/browser/renderer_host/media/video_capture_texture_wrapper.h"
 
 #include "base/bind.h"
 #include "content/browser/compositor/image_transport_factory.h"
 #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
 #include "content/browser/gpu/browser_gpu_memory_buffer_manager.h"
@@ skipping 80 matching lines @@
   DCHECK(gpu_channel_host);
   return CreateContextCommon(gpu_channel_host, 0);
 }
 
 typedef base::Callback<void(scoped_refptr<ContextProviderCommandBuffer>)>
     ProcessContextCallback;
 
 void CreateContextOnUIThread(ProcessContextCallback bottom_half) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   bottom_half.Run(ContextProviderCommandBuffer::Create(
-      CreateOffscreenCommandBufferContext(), "Offscreen-CaptureThread"));
+      CreateOffscreenCommandBufferContext(), OFFSCREEN_VIDEO_CAPTURE_CONTEXT));
   return;
 }
 
 void ResetLostContextCallback(
     const scoped_refptr<ContextProviderCommandBuffer>& capture_thread_context) {
   capture_thread_context->SetLostContextCallback(
       cc::ContextProvider::LostContextCallback());
 }
 
 }  // anonymous namespace
@@ skipping 342 matching lines @@
 void VideoCaptureTextureWrapper::TextureWrapperDelegate::OnError(
     const std::string& message) {
   DCHECK(capture_task_runner_->BelongsToCurrentThread());
   DLOG(ERROR) << message;
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&VideoCaptureController::DoErrorOnIOThread, controller_));
 }
 
 }  // namespace content