Change GPUInfo to handle multiple GPUs.

content/browser/gpu/gpu_data_manager_impl.h

 // 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.
 
 #ifndef CONTENT_BROWSER_GPU_GPU_DATA_MANAGER_IMPL_H_
 #define CONTENT_BROWSER_GPU_GPU_DATA_MANAGER_IMPL_H_
 #pragma once
 
 #include <set>
 #include <string>
@@ skipping 63 matching lines @@
   // If flags hasn't been set and GPUInfo is available, run through blacklist
   // and compute the flags.
   void UpdateGpuFeatureType(content::GpuFeatureType embedder_feature_type);
 
   // Notify all observers whenever there is a GPU info update.
   void NotifyGpuInfoUpdate();
 
   // If use-gl switch is osmesa or any, return true.
   bool UseGLIsOSMesaOrAny();
 
-  // Merges the second GPUInfo object with the first.
-  // If it's the same GPU, i.e., device id and vendor id are the same, then
-  // copy over the fields that are not set yet and ignore the rest.
-  // If it's a different GPU, then reset and copy over everything.
-  // Return true if something changes that may affect blacklisting; currently
-  // they are device_id, vendor_id, driver_vendor, driver_version, driver_date,
-  // and gl_renderer.
-  static bool Merge(content::GPUInfo* object, const content::GPUInfo& other);

[Ken Russell (switch to Gerrit), 2012/05/10 01:11:09]

Was removing this method intentional? If the GPU process fails to collect GPU
information and manages to send back an empty GPUInfo to the browser process, it
looks like the browser process will always overwrite its possibly better
information. Is that what was happening on Optimus machines before this CL? Is
the new behavior better or worse than the earlier behavior?

[Zhenyao Mo, 2012/05/10 21:55:32]

The removal of this Merge function is on purpose.  It's very easy to miss this
function when we add new fields to the GPUInfo, and the optimization we lose
without Merge is ignorable (we always re-run blacklist logic when we launch GPU
process).

However, you are right, I failed to consider the case where GPU process side
info collection fails.  Fixed in the new CL.

-
   // Try to switch to software rendering, if possible and necessary.
   void EnableSoftwareRenderingIfNecessary();
 
   bool complete_gpu_info_already_requested_;
   bool complete_gpu_info_available_;
 
   content::GpuFeatureType gpu_feature_type_;
   content::GpuFeatureType preliminary_gpu_feature_type_;
 
   content::GPUInfo gpu_info_;
   mutable base::Lock gpu_info_lock_;
 
   // Observers.
   const scoped_refptr<GpuDataManagerObserverList> observer_list_;
 
   ListValue log_messages_;
   bool software_rendering_;
 
   FilePath swiftshader_path_;
 
   // Current card force-blacklisted due to GPU crashes.
   bool card_blacklisted_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuDataManagerImpl);
 };
 
 #endif  // CONTENT_BROWSER_GPU_GPU_DATA_MANAGER_IMPL_H_