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

content/common/gpu/gpu_command_buffer_stub.cc

Index: content/common/gpu/gpu_command_buffer_stub.cc
diff --git a/content/common/gpu/gpu_command_buffer_stub.cc b/content/common/gpu/gpu_command_buffer_stub.cc
index 189215122af0bff2aeb71e88d7364c1a7ad0fe21..77ec5feadef637fb7d8b3c8c37cee2de2fd14d00 100644
--- a/content/common/gpu/gpu_command_buffer_stub.cc
+++ b/content/common/gpu/gpu_command_buffer_stub.cc
@@ -946,6 +946,10 @@ void GpuCommandBufferStub::OnRegisterGpuMemoryBuffer(
   if (decoder_) {
     gpu::gles2::ImageManager* image_manager = decoder_->GetImageManager();
     DCHECK(image_manager);
+    if (id <= 0) {

[reveman, 2014/07/25 19:00:23]

I don't think this check should exist. Either we change the IPC to uint32 or fix
so int32 is properly supported. I vote for the later as it looks like all we
have to do is int32 instead uint32 as the key in the image manager hash_map.

[sohanjg, 2014/07/26 10:42:22]

Done.

+      LOG(ERROR) << "Cannot add image with non-positive ID.";
+      return;
+    }
     image_manager->AddImage(image.get(), id);

[reveman, 2014/07/25 19:00:23]

You need to check for collisions before this call. We can't add the image if one
already exists with the same ID.

[sohanjg, 2014/07/26 10:42:23]

Done.

   }
 }
@@ -956,6 +960,11 @@ void GpuCommandBufferStub::OnDestroyGpuMemoryBuffer(int32 id) {
   if (decoder_) {
     gpu::gles2::ImageManager* image_manager = decoder_->GetImageManager();
     DCHECK(image_manager);
+    if (id <= 0) {

[reveman, 2014/07/25 19:00:23]

this check shouldn't exist.

[sohanjg, 2014/07/26 10:42:22]

Done.

+      LOG(ERROR) << "Cannot remove image with non-positive ID.";
+      return;
+    }
+    DCHECK(image_manager->LookupImage(id));

[reveman, 2014/07/25 19:00:23]

A DCHECK is not OK here. We need to log an error and early out to be sure that a
compromised renderer can't cause the GPU process to crash or behave in undefined
way.

[sohanjg, 2014/07/26 10:42:23]

Done.

     image_manager->RemoveImage(id);
   }
 }