Do not allocate depth-stencil buffers for GLSurfaces.

ui/gfx/gl/gl_surface_wgl.cc

 // Copyright (c) 2011 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/gfx/gl/gl_surface_wgl.h"
 
 #include "base/logging.h"
 #include "ui/gfx/gl/gl_bindings.h"
 #include "ui/gfx/gl/gl_implementation.h"
 
 namespace gfx {
 
 static ATOM g_class_registration;
 static HWND g_window;
 HDC g_display_dc;
 static int g_pixel_format = 0;
 
 const PIXELFORMATDESCRIPTOR kPixelFormatDescriptor = {
   sizeof(kPixelFormatDescriptor),    // Size of structure.
   1,                       // Default version.
   PFD_DRAW_TO_WINDOW |     // Window drawing support.
   PFD_SUPPORT_OPENGL |     // OpenGL support.
   PFD_DOUBLEBUFFER,        // Double buffering support (not stereo).
   PFD_TYPE_RGBA,           // RGBA color mode (not indexed).
   24,                      // 24 bit color mode.
   0, 0, 0, 0, 0, 0,        // Don't set RGB bits & shifts.
   8, 0,                    // 8 bit alpha
   0,                       // No accumulation buffer.
   0, 0, 0, 0,              // Ignore accumulation bits.
-  24,                      // 24 bit z-buffer size.
-  8,                       // 8-bit stencil buffer.
+  0,                       // no z-buffer.
+  0,                       // no stencil buffer.
   0,                       // No aux buffer.
   PFD_MAIN_PLANE,          // Main drawing plane (not overlay).
   0,                       // Reserved.
   0, 0, 0,                 // Layer masks ignored.
 };
 
 static LRESULT CALLBACK IntermediateWindowProc(HWND window,
                                                UINT message,
                                                WPARAM w_param,
                                                LPARAM l_param) {
@@ skipping 291 matching lines @@
 
 gfx::Size PbufferGLSurfaceWGL::GetSize() {
   return size_;
 }
 
 void* PbufferGLSurfaceWGL::GetHandle() {
   return device_context_;
 }
 
 }  // namespace gfx