Allow tests to stub out GL draw calls.

ui/gl/gl_surface.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 "ui/gl/gl_surface.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 51 matching lines @@
                   InitializeOneOffInternal();
   }
 
   if (initialized) {
     DVLOG(1) << "Using "
              << GetGLImplementationName(GetGLImplementation())
              << " GL implementation.";
     if (CommandLine::ForCurrentProcess()->HasSwitch(
         switches::kEnableGPUServiceLogging))
       InitializeDebugGLBindings();
+    if (CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kDisableGLDrawingForTests))
+      InitializeNullDrawGLBindings();
   }
   return initialized;
 }
 
 GLSurface::GLSurface() {}
 
 bool GLSurface::Initialize() {
   return true;
 }
 
@@ skipping 172 matching lines @@
   return surface_->GetFormat();
 }
 
 VSyncProvider* GLSurfaceAdapter::GetVSyncProvider() {
   return surface_->GetVSyncProvider();
 }
 
 GLSurfaceAdapter::~GLSurfaceAdapter() {}
 
 }  // namespace gfx