adds WARP support to Chromium, for Metro mode only, on Windows 8

chrome/browser/gpu/gpu_pref_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 "chrome/browser/gpu/gl_string_manager.h"
+#include "chrome/browser/gpu/gpu_pref_manager.h"
 
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/gpu_data_manager.h"
+#include "gpu/config/gpu_info.h"
 
 // static
-void GLStringManager::RegisterPrefs(PrefRegistrySimple* registry) {
+void GpuPrefManager::RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterStringPref(prefs::kGLVendorString, std::string());
   registry->RegisterStringPref(prefs::kGLRendererString, std::string());
   registry->RegisterStringPref(prefs::kGLVersionString, std::string());
+  registry->RegisterBooleanPref(prefs::kGPUUseWarp, false);
 }
 
-GLStringManager::GLStringManager() {
+GpuPrefManager::GpuPrefManager() {

[Zhenyao Mo, 2014/08/20 21:02:09]

You need to initialize use_warp_ here.

[luken, 2014/08/27 20:43:46]

Deprecated code.

 }
 
-GLStringManager::~GLStringManager() {
+GpuPrefManager::~GpuPrefManager() {
 }
 
-void GLStringManager::Initialize() {
-  // On MacOSX or Windows, preliminary GPUInfo is enough.
-#if defined(OS_LINUX)
+void GpuPrefManager::Initialize() {
+#if defined(OS_LINUX) || defined(OS_WIN)
   // We never remove this observer from GpuDataManager.
   content::GpuDataManager::GetInstance()->AddObserver(this);
 
   PrefService* local_state = g_browser_process->local_state();
   if (!local_state)
     return;
 
+#if defined(OS_LINUX)
   gl_vendor_ = local_state->GetString(prefs::kGLVendorString);
   gl_renderer_ = local_state->GetString(prefs::kGLRendererString);
   gl_version_ = local_state->GetString(prefs::kGLVersionString);
-
   if (!gl_vendor_.empty() || !gl_renderer_.empty() || !gl_version_.empty()) {
     content::GpuDataManager::GetInstance()->SetGLStrings(
         gl_vendor_, gl_renderer_, gl_version_);
   }
+#elif defined(OS_WIN)
+  use_warp_ = local_state->GetBoolean(prefs::kGPUUseWarp);
+  content::GpuDataManager::GetInstance()->SetShouldUseWarp(use_warp_);
 #endif
+
+#endif  // defined(OS_LINUX) || defined(OS_WIN)
 }
 
-void GLStringManager::OnGpuInfoUpdate() {
+void GpuPrefManager::OnGpuInfoUpdate() {
   std::string gl_vendor, gl_renderer, gl_version;
   content::GpuDataManager::GetInstance()->GetGLStrings(
       &gl_vendor, &gl_renderer, &gl_version);
-
   PrefService* local_state = g_browser_process->local_state();
   if (!local_state)
     return;
 
   if (!gl_vendor.empty() && gl_vendor != gl_vendor_) {
     gl_vendor_ = gl_vendor;
     local_state->SetString(prefs::kGLVendorString, gl_vendor_);
   }
   if (!gl_renderer.empty() && gl_renderer != gl_renderer_) {
     gl_renderer_ = gl_renderer;
     local_state->SetString(prefs::kGLRendererString, gl_renderer_);
   }
   if (!gl_version.empty() && gl_version != gl_version_) {
     gl_version_ = gl_version;
     local_state->SetString(prefs::kGLVersionString, gl_version_);
   }
+
+  // GpuDataManager::ShouldUseWarp() may reflect command-line settings as well
+  // as saved state, so we query the value of the GPUInfo field, as it should
+  // only reflect the desired persistent state of use_warp.
+  bool use_warp = content::GpuDataManager::GetInstance()->GetGPUInfo().use_warp;
+  if (use_warp != use_warp_) {
+    use_warp_ = use_warp;
+    local_state->SetBoolean(prefs::kGPUUseWarp, use_warp_);

[sky, 2014/08/20 22:37:03]

Why do we need to cache this in prefs? Can't we look it up at startup time?

[luken, 2014/08/27 20:43:46]

No longer cached. We now determine at startup time.

+    local_state->CommitPendingWrite();

[Zhenyao Mo, 2014/08/20 21:02:09]

Is CommitPendingWrite() necessary?

[sky, 2014/08/20 22:37:03]

Also, do you really need to cache use_warp_? Can you always SetBoolean?

[luken, 2014/08/27 20:43:46]

Deprecated code.

[luken, 2014/08/27 20:43:46]

Deprecated code.

+  }
 }