Command buffer should not report depth_texture on pure ES3 without depth_texture extension.

gpu/command_buffer/service/feature_info.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/feature_info.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <vector>
@@ skipping 493 matching lines @@
   // Therefore we made up GL_GOOGLE_depth_texture / GL_CHROMIUM_depth_texture.
   //
   // GL_GOOGLE_depth_texture is legacy. As we exposed it into NaCl we can't
   // get rid of it.
   //
   bool enable_depth_texture = false;
   if (!workarounds_.disable_depth_texture &&
       (extensions.Contains("GL_ARB_depth_texture") ||
        extensions.Contains("GL_OES_depth_texture") ||
        extensions.Contains("GL_ANGLE_depth_texture") ||
-       gl_version_info_->is_es3 ||
        gl_version_info_->is_desktop_core_profile)) {
+    // Note that we don't expose depth_texture extenion on top of ES3 if
+    // the depth_texture extension isn't exposed by the ES3 driver.
+    // This is because depth textures are filterable under linear mode in
+    // ES2 + extension, but not in core ES3.
     enable_depth_texture = true;
     feature_flags_.angle_depth_texture =
         extensions.Contains("GL_ANGLE_depth_texture");
   }
 
   if (enable_depth_texture) {
     AddExtensionString("GL_CHROMIUM_depth_texture");
     AddExtensionString("GL_GOOGLE_depth_texture");
     validators_.texture_internal_format.AddValue(GL_DEPTH_COMPONENT);
     validators_.texture_format.AddValue(GL_DEPTH_COMPONENT);
@@ skipping 1006 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu