Add a --use-angle flag for selecting the ANGLE renderer.

content/browser/gpu/gpu_data_manager_impl_private.cc

 // Copyright (c) 2013 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 "content/browser/gpu/gpu_data_manager_impl_private.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
@@ skipping 394 matching lines @@
   return use_swiftshader_;
 }
 
 void GpuDataManagerImplPrivate::RegisterSwiftShaderPath(
     const base::FilePath& path) {
   swiftshader_path_ = path;
   EnableSwiftShaderIfNecessary();
 }
 
 bool GpuDataManagerImplPrivate::ShouldUseWarp() const {
-  return use_warp_ ||
-         base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseWarp);
+  std::string angle_impl_flag =
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          switches::kUseANGLE);
+  return use_warp_ || angle_impl_flag == gfx::kANGLEImplementationWARPName;

[Zhenyao Mo, 2015/05/07 22:08:35]

The only place use_warp_ is set to true is ForceWarpModeForTesting(), which is
not referenced.  So you should just remove both.

[Geoff Lang, 2015/05/11 13:31:50]

Looks like use_warp_ is referenced in
GpuDataManagerImplPrivate::EnableWarpIfNecessary too but doesn't show up on the
code search because it is only compiled on Windows.

 }
 
 void GpuDataManagerImplPrivate::AddObserver(GpuDataManagerObserver* observer) {
   GpuDataManagerImpl::UnlockedSession session(owner_);
   observer_list_->AddObserver(observer);
 }
 
 void GpuDataManagerImplPrivate::RemoveObserver(
     GpuDataManagerObserver* observer) {
   GpuDataManagerImpl::UnlockedSession session(owner_);
@@ skipping 246 matching lines @@
   // collect full info (on Linux) and for crash reporting purpose.
   command_line->AppendSwitchASCII(switches::kGpuVendorID,
       base::StringPrintf("0x%04x", gpu_info_.gpu.vendor_id));
   command_line->AppendSwitchASCII(switches::kGpuDeviceID,
       base::StringPrintf("0x%04x", gpu_info_.gpu.device_id));
   command_line->AppendSwitchASCII(switches::kGpuDriverVendor,
       gpu_info_.driver_vendor);
   command_line->AppendSwitchASCII(switches::kGpuDriverVersion,
       gpu_info_.driver_version);
 
-  if (ShouldUseWarp())
-    command_line->AppendSwitch(switches::kUseWarp);
+  if (ShouldUseWarp() &&
+      !command_line->HasSwitch(switches::kUseANGLE)) {
+    command_line->AppendSwitchASCII(switches::kUseANGLE,
+        gfx::kANGLEImplementationWARPName);
+  }
 }
 
 void GpuDataManagerImplPrivate::AppendPluginCommandLine(
     base::CommandLine* command_line) const {
   DCHECK(command_line);
 
 #if defined(OS_MACOSX)
   // TODO(jbauman): Add proper blacklist support for core animation plugins so
   // special-casing this video card won't be necessary. See
   // http://crbug.com/134015
@@ skipping 487 matching lines @@
   gpu_info_.context_info_state = gpu::kCollectInfoFatalFailure;
 #if defined(OS_WIN)
   gpu_info_.dx_diagnostics_info_state = gpu::kCollectInfoFatalFailure;
 #endif
   complete_gpu_info_already_requested_ = true;
   // Some observers might be waiting.
   NotifyGpuInfoUpdate();
 }
 
 }  // namespace content