Use GpuPreferences to avoid directly accessing switches in gpu related code

android_webview/browser/deferred_gpu_command_service.cc

Index: android_webview/browser/deferred_gpu_command_service.cc
diff --git a/android_webview/browser/deferred_gpu_command_service.cc b/android_webview/browser/deferred_gpu_command_service.cc
index a9fd6a2c19d95e463a4bb3dc4a1036122ea0d477..cc9e0a14a2460f49aea0265964ff0fb7fca04b16 100644
--- a/android_webview/browser/deferred_gpu_command_service.cc
+++ b/android_webview/browser/deferred_gpu_command_service.cc
@@ -6,19 +6,34 @@
 
 #include "android_webview/browser/gl_view_renderer_manager.h"
 #include "android_webview/browser/shared_renderer_state.h"
+#include "base/command_line.h"
 #include "base/lazy_instance.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/trace_event/trace_event.h"
 #include "content/public/browser/android/synchronous_compositor.h"
 #include "gpu/command_buffer/service/framebuffer_completeness_cache.h"
+#include "gpu/command_buffer/service/gpu_switches.h"
 #include "gpu/command_buffer/service/shader_translator_cache.h"
 #include "gpu/command_buffer/service/sync_point_manager.h"
+#include "gpu/config/gpu_switches.h"
+#include "ui/gl/gl_switches.h"
 
 namespace android_webview {
 
 namespace {
 base::LazyInstance<scoped_refptr<DeferredGpuCommandService> >
     g_service = LAZY_INSTANCE_INITIALIZER;
+
+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
 
 base::LazyInstance<base::ThreadLocalBoolean> ScopedAllowGL::allow_gl;
@@ -63,7 +78,10 @@ DeferredGpuCommandService* DeferredGpuCommandService::GetInstance() {
 }
 
 DeferredGpuCommandService::DeferredGpuCommandService()
-    : sync_point_manager_(new gpu::SyncPointManager(true)) {}
+    : gpu::InProcessCommandBuffer::Service(gpu_preferences_),

[piman, 2016/02/25 21:56:05]

Oh, this is confusing/dangerous (and probably undefined behavior). We give
InProcessCommandBuffer::Service a set of uninitialized preferences, and then
change them. If InProcessCommandBuffer::Service uses the preferences in the
constructor, things will blow up.

How about instead: have InProcessCommandBuffer::Service own the GpuPreferences,
and we just create a GetGpuPreferences function that returns the GpuPreferences
initialized from the command line.

DeferredGpuCommandService::DeferredGpuCommandService()
    : gpu::InProcessCommandBuffer::Service(GetGpuPreferences()),
      sync_point_manager_(new gpu::SyncPointManager(true)) {
  [...]
}

[Peng, 2016/02/25 22:29:08]

Done.

+      sync_point_manager_(new gpu::SyncPointManager(true)) {
+  InitGpuPreferences();
+}
 
 DeferredGpuCommandService::~DeferredGpuCommandService() {
   base::AutoLock lock(tasks_lock_);
@@ -95,6 +113,58 @@ void DeferredGpuCommandService::ScheduleTask(const base::Closure& task) {
   }
 }
 
+void DeferredGpuCommandService::InitGpuPreferences() {
+  DCHECK(base::CommandLine::InitializedForCurrentProcess());
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  gpu_preferences_.single_process = true;
+  gpu_preferences_.in_process_gpu = true;
+  // TODO(penghuang): share below code with content/gpu/gpu_child_thread.cc
+  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 (GetSizeTFromSwitch(command_line, switches::kForceGpuMemAvailableMb,
+                         &gpu_preferences_.force_gpu_mem_available)) {
+    gpu_preferences_.force_gpu_mem_available *= 1024 * 1024;
+  }
+  if (GetSizeTFromSwitch(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_gl_path_rendering =
+    command_line->HasSwitch(switches::kEnableGLPathRendering);
+  gpu_preferences_.enable_gpu_service_logging =
+      command_line->HasSwitch(switches::kEnableGPUServiceLogging);
+  gpu_preferences_.enable_gpu_service_tracing =
+}
+
 size_t DeferredGpuCommandService::IdleQueueSize() {
   base::AutoLock lock(tasks_lock_);
   return idle_tasks_.size();
@@ -149,8 +219,10 @@ bool DeferredGpuCommandService::UseVirtualizedGLContexts() { return true; }
 
 scoped_refptr<gpu::gles2::ShaderTranslatorCache>
 DeferredGpuCommandService::shader_translator_cache() {
-  if (!shader_translator_cache_.get())
-    shader_translator_cache_ = new gpu::gles2::ShaderTranslatorCache;
+  if (!shader_translator_cache_.get()) {
+    shader_translator_cache_ =
+        new gpu::gles2::ShaderTranslatorCache(gpu_preferences());
+  }
   return shader_translator_cache_;
 }