Use stub GL draw/clear calls for browser tests that do not need pixels.

content/browser/gpu/gpu_process_host.cc

 // 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.
 
 #include "content/browser/gpu/gpu_process_host.h"
 
 #include "base/base64.h"
 #include "base/base_switches.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 1096 matching lines @@
   cmd_line->AppendSwitchASCII(switches::kProcessType, switches::kGpuProcess);
   cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id);
 
   if (kind_ == GPU_PROCESS_KIND_UNSANDBOXED)
     cmd_line->AppendSwitch(switches::kDisableGpuSandbox);
 
   // Propagate relevant command line switches.
   static const char* const kSwitchNames[] = {
     switches::kDisableAcceleratedVideoDecode,
     switches::kDisableBreakpad,
+    switches::kDisableGLDrawingForTests,
     switches::kDisableGLMultisampling,
     switches::kDisableGpuSandbox,
     switches::kDisableGpuWatchdog,
     switches::kDisableImageTransportSurface,
     switches::kDisableLogging,
     switches::kDisableSeccompFilterSandbox,
 #if defined(ENABLE_WEBRTC)
     switches::kDisableWebRtcHWEncoding,
 #endif
     switches::kEnableLogging,
@@ skipping 130 matching lines @@
   TRACE_EVENT0("gpu", "GpuProcessHost::OnCacheShader");
   ClientIdToShaderCacheMap::iterator iter =
       client_id_to_shader_cache_.find(client_id);
   // If the cache doesn't exist then this is an off the record profile.
   if (iter == client_id_to_shader_cache_.end())
     return;
   iter->second->Cache(GetShaderPrefixKey() + ":" + key, shader);
 }
 
 }  // namespace content