During image destroy, delete textures only if we have a GL context.

gpu/command_buffer/service/image_manager.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/image_manager.h"
 
 #include "ui/gl/gl_image.h"
 
 namespace gpu {
 namespace gles2 {
 
 ImageManager::ImageManager() : release_after_use_(false) {
 }
 
 ImageManager::~ImageManager() {
 }
 
+void ImageManager::Destroy(bool have_context) {
+  for (GLImageMap::const_iterator iter = gl_images_.begin();
+       iter != gl_images_.end();
+       ++iter)
+    iter->second.get()->Destroy(have_context);
+  gl_images_.clear();
+}
+
 void ImageManager::RegisterGpuMemoryBuffer(int32 id,
                                            gfx::GpuMemoryBufferHandle buffer,
                                            size_t width,
                                            size_t height,
                                            unsigned internalformat) {
   if (id <= 0) {
     DVLOG(0) << "Cannot register GPU memory buffer with non-positive ID.";
     return;
   }
 
   if (LookupImage(id)) {
     DVLOG(0) << "GPU memory buffer ID already in use.";
     return;
   }
 
   scoped_refptr<gfx::GLImage> gl_image =
       gfx::GLImage::CreateGLImageForGpuMemoryBuffer(buffer,
                                                     gfx::Size(width, height),
                                                     internalformat);
   if (!gl_image)
     return;
 
   if (release_after_use_)
     gl_image->SetReleaseAfterUse();
 
   AddImage(gl_image.get(), id);
 }
 
 void ImageManager::UnregisterGpuMemoryBuffer(int32 id) {
+  gfx::GLImage* image = LookupImage(id);
+  DCHECK(image);

[reveman, 2014/06/03 13:57:39]

What's preventing a malicous renderer from using an invalid id and causing this
to crash?

[sohanjg, 2014/06/03 15:09:20]

Done.

+  image->Destroy(true);
   RemoveImage(id);
 }
 
 void ImageManager::AddImage(gfx::GLImage* image, int32 service_id) {
   gl_images_[service_id] = image;
 }
 
 void ImageManager::RemoveImage(int32 service_id) {
   gl_images_.erase(service_id);
 }
 
 gfx::GLImage* ImageManager::LookupImage(int32 service_id) {
   GLImageMap::const_iterator iter = gl_images_.find(service_id);
   if (iter != gl_images_.end())
     return iter->second.get();
 
   return NULL;
 }
 
 void ImageManager::SetReleaseAfterUse() {
   release_after_use_ = true;
 }
 
 }  // namespace gles2
 }  // namespace gpu