[Android WebView] Clean up global GL resource pt.1

content/renderer/media/android/stream_texture_factory_android_synchronous_impl.cc

 // 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.
 
 #include "content/renderer/media/android/stream_texture_factory_android_synchronous_impl.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 106 matching lines @@
 }  // namespace
 
 StreamTextureFactorySynchronousImpl::StreamTextureFactorySynchronousImpl(
     ContextProvider* context_provider,
     int view_id)
     : context_provider_(context_provider), view_id_(view_id) {}
 
 StreamTextureFactorySynchronousImpl::~StreamTextureFactorySynchronousImpl() {}
 
 StreamTextureProxy* StreamTextureFactorySynchronousImpl::CreateProxy() {
+  if (!context_provider_)
+    return NULL;
   return new StreamTextureProxyImpl(context_provider_);
 }
 
 void StreamTextureFactorySynchronousImpl::EstablishPeer(int32 stream_id,
                                                         int player_id) {
+  DCHECK(context_provider_);
   scoped_refptr<gfx::SurfaceTexture> surface_texture =
       context_provider_->GetSurfaceTexture(stream_id);
   if (surface_texture) {
     SurfaceTexturePeer::GetInstance()->EstablishSurfaceTexturePeer(
         base::Process::Current().handle(),
         surface_texture,
         view_id_,
         player_id);
   }
 }
 
 unsigned StreamTextureFactorySynchronousImpl::CreateStreamTexture(
     unsigned texture_target,
     unsigned* texture_id,
     gpu::Mailbox* texture_mailbox,
     unsigned* texture_mailbox_sync_point) {
+  DCHECK(context_provider_);
   WebKit::WebGraphicsContext3D* context = context_provider_->Context3d();
   unsigned stream_id = 0;
   if (context->makeContextCurrent()) {
     *texture_id = context->createTexture();
     stream_id = context->createStreamTextureCHROMIUM(*texture_id);
 
     context->genMailboxCHROMIUM(texture_mailbox->name);
     context->bindTexture(texture_target, *texture_id);
     context->produceTextureCHROMIUM(texture_target, texture_mailbox->name);
 
     context->flush();
     *texture_mailbox_sync_point = context->insertSyncPoint();
   }
   return stream_id;
 }
 
 void StreamTextureFactorySynchronousImpl::DestroyStreamTexture(
     unsigned texture_id) {
+  DCHECK(context_provider_);
   WebKit::WebGraphicsContext3D* context = context_provider_->Context3d();
   if (context->makeContextCurrent()) {
     context->destroyStreamTextureCHROMIUM(texture_id);
     context->deleteTexture(texture_id);
     context->flush();
   }
 }
 
 void StreamTextureFactorySynchronousImpl::SetStreamTextureSize(
     int32 stream_id,
     const gfx::Size& size) {}
 
 }  // namespace content