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

ui/gl/gl_context_stub_with_extensions.cc

 // Copyright 2014 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 "ui/gl/gl_context_stub_with_extensions.h"
 
 namespace gfx {
 
 void GLContextStubWithExtensions::AddExtensionsString(const char* extensions) {
   if (extensions == NULL)
     return;
 
   if (extensions_.size() != 0)
     extensions_ += ' ';
   extensions_ += extensions;
 }
 
 std::string GLContextStubWithExtensions::GetExtensions() {
   return extensions_;
 }
 
 void GLContextStubWithExtensions::SetGLVersionString(const char* version_str) {
   version_str_ = std::string(version_str ? version_str : "");
 }
 
 std::string GLContextStubWithExtensions::GetGLVersion() {
   return version_str_;
 }
 
+bool GLContextStubWithExtensions::WasAllocatedUsingRobustnessExtension() {
+  return HasExtension("GL_ARB_robustness") ||
+         HasExtension("GL_KHR_robustness") ||
+         HasExtension("GL_EXT_robustness");
+}
+
 }  // namespace gfx