Get rid of gpu related switches by passing gpu::GpuPreferences via IPC.

content/public/browser/gpu_utils.cc

+// 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 "content/public/browser/gpu_utils.h"
+
+#include "base/command_line.h"
+#include "base/lazy_instance.h"
+#include "base/strings/string_number_conversions.h"
+#include "content/public/common/content_switches.h"
+#include "gpu/command_buffer/service/gpu_switches.h"
+#include "gpu/config/gpu_switches.h"
+#include "ui/gl/gl_switches.h"
+
+namespace {
+
+bool GetUintFromSwitch(const base::CommandLine* command_line,
+                       const base::StringPiece& switch_string,
+                       uint32_t* value) {
+  if (!command_line->HasSwitch(switch_string))
+    return false;
+  std::string switch_value(command_line->GetSwitchValueASCII(switch_string));
+  return base::StringToUint(switch_value, value);
+}
+
+void InitGpuPreferencesFromCommandLine(gpu::GpuPreferences* gpu_preferences) {
+  DCHECK(base::CommandLine::InitializedForCurrentProcess());
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  gpu_preferences->single_process =
+      command_line->HasSwitch(switches::kSingleProcess);
+  gpu_preferences->in_process_gpu =
+      command_line->HasSwitch(switches::kInProcessGPU);
+  gpu_preferences->ui_prioritize_in_gpu_process =
+      command_line->HasSwitch(switches::kUIPrioritizeInGpuProcess);
+  gpu_preferences->compile_shader_always_succeeds =
+      command_line->HasSwitch(switches::kCompileShaderAlwaysSucceeds);
+  gpu_preferences->disable_gl_error_limit =
+    command_line->HasSwitch(switches::kDisableGLErrorLimit);
+  gpu_preferences->disable_glsl_translator =
+    command_line->HasSwitch(switches::kDisableGLSLTranslator);
+  gpu_preferences->disable_gpu_driver_bug_workarounds =
+    command_line->HasSwitch(switches::kDisableGpuDriverBugWorkarounds);
+  gpu_preferences->disable_shader_name_hashing =
+    command_line->HasSwitch(switches::kDisableShaderNameHashing);
+  gpu_preferences->enable_gpu_command_logging =
+    command_line->HasSwitch(switches::kEnableGPUCommandLogging);
+  gpu_preferences->enable_gpu_debugging =
+    command_line->HasSwitch(switches::kEnableGPUDebugging);
+  gpu_preferences->enable_gpu_service_logging_gpu =
+    command_line->HasSwitch(switches::kEnableGPUServiceLoggingGPU);
+  gpu_preferences->disable_gpu_program_cache =
+    command_line->HasSwitch(switches::kDisableGpuProgramCache);
+  gpu_preferences->enforce_gl_minimums =
+    command_line->HasSwitch(switches::kEnforceGLMinimums);
+  if (GetUintFromSwitch(command_line, switches::kForceGpuMemAvailableMb,
+                        &gpu_preferences->force_gpu_mem_available)) {
+    gpu_preferences->force_gpu_mem_available *= 1024 * 1024;
+  }
+  if (GetUintFromSwitch(command_line, switches::kGpuProgramCacheSizeKb,
+                        &gpu_preferences->gpu_program_cache_size)) {
+    gpu_preferences->gpu_program_cache_size *= 1024;
+  }
+  gpu_preferences->enable_share_group_async_texture_upload =
+    command_line->HasSwitch(switches::kEnableShareGroupAsyncTextureUpload);
+  gpu_preferences->enable_subscribe_uniform_extension =
+    command_line->HasSwitch(switches::kEnableSubscribeUniformExtension);
+  gpu_preferences->enable_threaded_texture_mailboxes =
+    command_line->HasSwitch(switches::kEnableThreadedTextureMailboxes);
+  gpu_preferences->gl_shader_interm_output =
+    command_line->HasSwitch(switches::kGLShaderIntermOutput);
+  gpu_preferences->emulate_shader_precision =
+    command_line->HasSwitch(switches::kEmulateShaderPrecision);
+  gpu_preferences->enable_gpu_service_logging =
+      command_line->HasSwitch(switches::kEnableGPUServiceLogging);
+  gpu_preferences->enable_gpu_service_tracing =
+      command_line->HasSwitch(switches::kEnableGPUServiceTracing);
+  gpu_preferences->enable_unsafe_es3_apis =
+    command_line->HasSwitch(switches::kEnableUnsafeES3APIs);
+}
+
+using base::internal::LeakyLazyInstanceTraits;
+struct LeakyGpuPreferencesTraits
+    : LeakyLazyInstanceTraits<gpu::GpuPreferences> {
+  static gpu::GpuPreferences* New(void* instance) {
+    gpu::GpuPreferences* gpu_preferences =
+        LeakyLazyInstanceTraits<gpu::GpuPreferences>::New(instance);
+    InitGpuPreferencesFromCommandLine(gpu_preferences);
+    return gpu_preferences;
+  }
+};
+
+base::LazyInstance<gpu::GpuPreferences, LeakyGpuPreferencesTraits>
+    g_gpu_preferences = LAZY_INSTANCE_INITIALIZER;

[piman, 2016/03/03 20:18:12]

Do we need this global, in particular, do we need it to be leaky? It doesn't
seem overly taxing to return a gpu::GpuPreferences from GetGpuPreferences()
(rather than a const&), I suppose it means we may re-parse the command-line
flags, but we're already doing that today - this is so seldom (restarting the
GPU process) that we shouldn't worry about it. OTOH, it makes testing possibly
harder (test side effects, if one tries to change the command line, it may not
apply any more).

[Peng, 2016/03/03 22:20:55]

Done.

+
+}  // namespace
+
+namespace content {
+
+const gpu::GpuPreferences& GetGpuPreferences() {
+  return g_gpu_preferences.Get();
+}
+
+}  // namespace content