Add GL_EXT_multisampled_render_to_texture support to command buffer.

gpu/command_buffer/service/context_group.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 "gpu/command_buffer/service/context_group.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 83 matching lines @@
   const GLint kMinRenderbufferSize = 512;  // GL says 1 pixel!
   GLint max_renderbuffer_size = 0;
   if (!QueryGLFeature(
       GL_MAX_RENDERBUFFER_SIZE, kMinRenderbufferSize,
       &max_renderbuffer_size)) {
     LOG(ERROR) << "ContextGroup::Initialize failed because maximum "
                << "renderbuffer size too small.";
     return false;
   }
   GLint max_samples = 0;
-  if (feature_info_->feature_flags().chromium_framebuffer_multisample) {
-    glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
+  if (feature_info_->feature_flags().chromium_framebuffer_multisample ||
+      feature_info_->feature_flags().multisampled_render_to_texture) {
+    if (feature_info_->feature_flags(
+            ).use_img_for_multisampled_render_to_texture) {
+      glGetIntegerv(GL_MAX_SAMPLES_IMG, &max_samples);
+    } else {
+      glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
+    }
   }
 
   if (feature_info_->feature_flags().ext_draw_buffers) {
     GetIntegerv(GL_MAX_COLOR_ATTACHMENTS_EXT, &max_color_attachments_);
     if (max_color_attachments_ < 1)
       max_color_attachments_ = 1;
     GetIntegerv(GL_MAX_DRAW_BUFFERS_ARB, &max_draw_buffers_);
     if (max_draw_buffers_ < 1)
       max_draw_buffers_ = 1;
     draw_buffer_ = GL_BACK;
@@ skipping 255 matching lines @@
     GLenum pname, GLint min_required, uint32* v) {
   uint32 value = 0;
   GetIntegerv(pname, &value);
   bool result = CheckGLFeatureU(min_required, &value);
   *v = value;
   return result;
 }
 
 }  // namespace gles2
 }  // namespace gpu