Use GpuPreferences to avoid directly accessing switches in gpu related code

gpu/command_buffer/service/gpu_preferences.cc

Index: gpu/command_buffer/service/gpu_preferences.cc
diff --git a/gpu/command_buffer/service/gpu_preferences.cc b/gpu/command_buffer/service/gpu_preferences.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f9b45480d8b41e5190ec4bed6290023777840677
--- /dev/null
+++ b/gpu/command_buffer/service/gpu_preferences.cc
@@ -0,0 +1,90 @@
+// Copyright 2016 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 "gpu/command_buffer/service/gpu_preferences.h"
+
+#include "base/command_line.h"
+#include "base/memory/singleton.h"
+#include "base/strings/string_number_conversions.h"
+#include "gpu/command_buffer/service/gpu_switches.h"
+#include "gpu/config/gpu_switches.h"
+#include "gpu/config/gpu_util.h"
+#include "ui/gl/gl_switches.h"
+
+namespace {
+
+bool GetSizeTFromSwitch(const base::CommandLine* command_line,
+                        const base::StringPiece& switch_string,
+                        size_t* value) {
+  if (!command_line->HasSwitch(switch_string))
+    return false;
+  std::string switch_value(command_line->GetSwitchValueASCII(switch_string));
+  return base::StringToSizeT(switch_value, value);
+}
+
+}  // namespace
+
+namespace gpu {
+
+GpuPreferences* GpuPreferences::GetInstance() {
+  return base::Singleton<GpuPreferences>::get();
+}
+
+GpuPreferences::GpuPreferences() {

[Fady Samuel, 2016/02/22 17:14:16]

Drive-by: I don't think we want a global object here. I think we want to plumb
this through to the relevant areas. Please discuss with piman@

[Peng, 2016/02/24 20:48:32]

Done.

+  if (!base::CommandLine::InitializedForCurrentProcess())
+    return;
+
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+
+  StringToFeatureSet(
+      command_line->GetSwitchValueASCII(switches::kGpuDriverBugWorkarounds),
+      &gpu_driver_bug_workarounds);
+  compile_shader_always_succeeds =
+      command_line->HasSwitch(switches::kCompileShaderAlwaysSucceeds);
+  disable_gl_error_limit =
+      command_line->HasSwitch(switches::kDisableGLErrorLimit);
+  disable_glsl_translator =
+      command_line->HasSwitch(switches::kDisableGLSLTranslator);
+  disable_gpu_driver_bug_workarounds =
+      command_line->HasSwitch(switches::kDisableGpuDriverBugWorkarounds);
+  disable_shader_name_hashing =
+      command_line->HasSwitch(switches::kDisableShaderNameHashing);
+  enable_gpu_command_logging =
+      command_line->HasSwitch(switches::kEnableGPUCommandLogging);
+  enable_gpu_debugging =
+      command_line->HasSwitch(switches::kEnableGPUDebugging);
+  enable_gpu_service_logging_gpu =
+      command_line->HasSwitch(switches::kEnableGPUServiceLoggingGPU);
+  disable_gpu_program_cache =
+      command_line->HasSwitch(switches::kDisableGpuProgramCache);
+  enforce_gl_minimums =
+      command_line->HasSwitch(switches::kEnforceGLMinimums);
+  if (GetSizeTFromSwitch(command_line, switches::kForceGpuMemAvailableMb,
+                         &force_gpu_mem_available)) {
+    force_gpu_mem_available *= 1024 * 1024;
+  }
+  if (GetSizeTFromSwitch(command_line, switches::kGpuProgramCacheSizeKb,
+                         &gpu_program_cache_size)) {
+    gpu_program_cache_size *= 1024;
+  }
+  enable_share_group_async_texture_upload =
+      command_line->HasSwitch(switches::kEnableShareGroupAsyncTextureUpload);
+  enable_subscribe_uniform_extension =
+      command_line->HasSwitch(switches::kEnableSubscribeUniformExtension);
+  enable_threaded_texture_mailboxes =
+      command_line->HasSwitch(switches::kEnableThreadedTextureMailboxes);
+  gl_shader_interm_output =
+      command_line->HasSwitch(switches::kGLShaderIntermOutput);
+  emulate_shader_precision =
+      command_line->HasSwitch(switches::kEmulateShaderPrecision);
+  enable_gl_path_rendering =
+      command_line->HasSwitch(switches::kEnableGLPathRendering);
+  enable_unsafe_es3_apis =
+      command_line->HasSwitch(switches::kEnableUnsafeES3APIs);
+}
+
+GpuPreferences::~GpuPreferences() {}
+
+}  // namespace gpu