Implement blacklist's force GPU capability in dual GPU machines.

content/public/common/gpu_switching_option.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_PUBLIC_COMMON_GPU_SWITCHING_OPTION_H_
+#define CONTENT_PUBLIC_COMMON_GPU_SWITCHING_OPTION_H_
+
+#include "build/build_config.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+enum GpuSwitchingOption {
+  GPU_SWITCHING_OPTION_AUTOMATIC,
+  GPU_SWITCHING_OPTION_FORCE_INTEGRATED,
+  GPU_SWITCHING_OPTION_FORCE_DISCRETE,
+  GPU_SWITCHING_OPTION_UNKNOWN
+};
+
+}  // namespace content
+
+CONTENT_EXPORT extern const char kGpuSwitchingOptionNameAutomatic[];

[jam, 2012/09/17 17:08:55]

why are these here? these belong in content\public\common\content_switches.h
with the rest of the command line flags or options

[Zhenyao Mo, 2012/09/17 17:13:43]

These are not just for commandline flags, they are also for gpu_blacklist and
about:gpu pages.  So putting them in a common place (here) seems like better
than putting them in the commandline options.

[jam, 2012/09/17 17:16:08]

right, I realize that. these are anagalous to kRendererProcess/kPluginProcess
etc, however as they are command line arguments, they're still in
content_switches.h

[Zhenyao Mo, 2012/09/17 17:28:58]

The commandline switch options only support force_discrete and force_integrated.
 We don't want to support automatic option because in older macbooks, automatic
switching cause disasters, whereas using only discrete GPU or integrated GPU
works fine.  So we hardwire to use discrete GPU on those machines, and we don't
want to provide an option to overwrite the force_discrete and starts automatic
switching.

So instead of sharing the strings here, I'll create two option strings in the
content_switches.h.

+CONTENT_EXPORT extern const char kGpuSwitchingOptionNameForceIntegrated[];
+CONTENT_EXPORT extern const char kGpuSwitchingOptionNameForceDiscrete[];
+
+#endif  // CONTENT_PUBLIC_COMMON_GPU_SWITCHING_OPTION_H_
+