Avoid unncessary EGLImageTargetTexture calls

gpu/command_buffer/service/texture_definition.cc

 // Copyright 2014 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/texture_definition.h"
 
 #include <list>
 
 #include "base/lazy_instance.h"
 #include "base/memory/linked_ptr.h"
@@ skipping 387 matching lines @@
 
 void TextureDefinition::UpdateTextureInternal(Texture* texture) const {
 #if DCHECK_IS_ON()
   DCHECK(g_inside_scoped_update_texture.Get().Get());
 #endif
   gfx::ScopedTextureBinder texture_binder(target_, texture->service_id());
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, min_filter_);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, mag_filter_);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrap_s_);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap_t_);
-  if (image_buffer_.get())
-    image_buffer_->BindToTexture(target_);
+
+  if (image_buffer_.get()) {
+    gfx::GLImage* existing_image = texture->GetLevelImage(target_, 0);
+    // Don't need to re-bind if already bound before.
+    if (!existing_image || !image_buffer_->IsClient(existing_image)) {
+      image_buffer_->BindToTexture(target_);
+    }
+  }
 
   if (defined_) {
     texture->face_infos_.resize(1);
     texture->face_infos_[0].level_infos.resize(1);
     texture->SetLevelInfo(NULL, level_info_.target, 0,
                           level_info_.internal_format, level_info_.width,
                           level_info_.height, level_info_.depth,
                           level_info_.border, level_info_.format,
                           level_info_.type, level_info_.cleared);
   }
@@ skipping 60 matching lines @@
 
   return true;
 }
 
 bool TextureDefinition::SafeToRenderFrom() const {
   return level_info_.cleared;
 }
 
 }  // namespace gles2
 }  // namespace gpu