Enforce no uncleared OES external textures. Clear in AVDA, not GVD.

gpu/command_buffer/service/gles2_cmd_decoder.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/gles2_cmd_decoder.h"
 
 #include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 12165 matching lines @@
 
 bool GLES2DecoderImpl::ClearLevel(Texture* texture,
                                   unsigned target,
                                   int level,
                                   unsigned format,
                                   unsigned type,
                                   int xoffset,
                                   int yoffset,
                                   int width,
                                   int height) {
-  DCHECK(target != GL_TEXTURE_3D && target != GL_TEXTURE_2D_ARRAY);
+  DCHECK(target != GL_TEXTURE_3D && target != GL_TEXTURE_2D_ARRAY &&
+         target != GL_TEXTURE_EXTERNAL_OES);
   uint32_t channels = GLES2Util::GetChannelsForFormat(format);
   if ((feature_info_->feature_flags().angle_depth_texture ||
        feature_info_->IsWebGL2OrES3Context())
       && (channels & GLES2Util::kDepth) != 0) {
     // It's a depth format and ANGLE doesn't allow texImage2D or texSubImage2D
     // on depth formats.
     GLuint fb = 0;
     glGenFramebuffersEXT(1, &fb);
     glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, fb);
 
@@ skipping 6599 matching lines @@
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu