Add a suppression for GLHelper blocking the UI thread.

content/common/gpu/client/gl_helper.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/common/gpu/client/gl_helper.h"
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread.h"
+#include "base/threading/thread_restrictions.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebCString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
 #include "ui/gfx/gl/gl_bindings.h"
 #include "ui/gfx/size.h"
 
 namespace {
 
 const char kGLHelperThreadName[] = "GLHelperThread";
 
 class GLHelperThread : public base::Thread {
@@ skipping 517 matching lines @@
   if (decremented_count == 0) {
     // When this is the last instance, we synchronize with the pending
     // operations on GLHelperThread. Otherwise on shutdown we may kill the GPU
     // process infrastructure (BrowserGpuChannelHostFactory) before they have
     // a chance to complete, likely leading to a crash.
     base::WaitableEvent event(false, false);
     g_gl_helper_thread.Pointer()->message_loop_proxy()->PostTask(
         FROM_HERE,
         base::Bind(&SignalWaitableEvent,
                    &event));
+    // http://crbug.com/125415
+    base::ThreadRestrictions::ScopedAllowWait allow_wait;
     event.Wait();
   }
 }
 
 WebKit::WebGraphicsContext3D* GLHelper::context() const {
   return context_;
 }
 
 void GLHelper::Detach() {
   if (copy_texture_to_impl_.get())
@@ skipping 44 matching lines @@
   WebKit::WGC3Dint compile_status = 0;
   context_->getShaderiv(shader, GL_COMPILE_STATUS, &compile_status);
   if (!compile_status) {
     LOG(ERROR) << std::string(context_->getShaderInfoLog(shader).utf8());
     return 0;
   }
   return shader.Detach();
 }
 
 }  // namespace content