Improve GL helpers.

mojo/gpu/gl_texture.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 "mojo/gpu/gl_texture.h"
 
 #include <GLES2/gl2.h>
 
 namespace mojo {
 
 GLTexture::GLTexture(base::WeakPtr<GLContext> context, mojo::Size size)
     : context_(context), size_(size), texture_id_(0u) {
   DCHECK(context_);
   context_->MakeCurrent();
   glGenTextures(1, &texture_id_);
   glBindTexture(GL_TEXTURE_2D, texture_id_);
   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, size_.width, size_.height, 0, GL_RGBA,
                GL_UNSIGNED_BYTE, 0);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glBindTexture(GL_TEXTURE_2D, 0);
 }
 
 GLTexture::~GLTexture() {
   if (context_) {
     context_->MakeCurrent();
     glDeleteTextures(1, &texture_id_);
   }
 }
 
 }  // namespace mojo