Make field trials activated in the GPU process be reflected in browser.

content/browser/gpu/gpu_process_host.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 "content/browser/gpu/gpu_process_host.h"
 
 #include <stddef.h>
 
+#include <algorithm>
+#include <list>
 #include <utility>
 
 #include "base/base64.h"
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/sha1.h"
 #include "base/threading/thread.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
 #include "components/tracing/common/tracing_switches.h"
 #include "content/browser/browser_child_process_host_impl.h"
 #include "content/browser/gpu/compositor_util.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
 #include "content/browser/gpu/gpu_process_host_ui_shim.h"
 #include "content/browser/gpu/shader_disk_cache.h"
@@ skipping 151 matching lines @@
       : cmd_line_(cmd_line) {}
 #elif defined(OS_POSIX)
       : ipc_fd_(host->TakeClientFileDescriptor()) {}
 #endif
 
   ~GpuSandboxedProcessLauncherDelegate() override {}
 
 #if defined(OS_WIN)
   bool ShouldSandbox() override {
     bool sandbox = !cmd_line_->HasSwitch(switches::kDisableGpuSandbox);
-    if(! sandbox) {
+    if (!sandbox) {
       DVLOG(1) << "GPU sandbox is disabled";
     }
     return sandbox;
   }
 
   bool DisableDefaultPolicy() override {
     return true;
   }
 
   // For the GPU process we gotten as far as USER_LIMITED. The next level
@@ skipping 420 matching lines @@
     IPC_MESSAGE_HANDLER(GpuHostMsg_DidDestroyOffscreenContext,
                         OnDidDestroyOffscreenContext)
     IPC_MESSAGE_HANDLER(GpuHostMsg_GpuMemoryUmaStats,
                         OnGpuMemoryUmaStatsReceived)
     IPC_MESSAGE_HANDLER(GpuHostMsg_DestroyChannel, OnDestroyChannel)
     IPC_MESSAGE_HANDLER(GpuHostMsg_CacheShader, OnCacheShader)
 #if defined(OS_WIN)
     IPC_MESSAGE_HANDLER(GpuHostMsg_AcceleratedSurfaceCreatedChildWindow,
                         OnAcceleratedSurfaceCreatedChildWindow)
 #endif
-
+    IPC_MESSAGE_HANDLER(GpuHostMsg_FieldTrialActivated, OnFieldTrialActivated);
     IPC_MESSAGE_UNHANDLED(RouteOnUIThread(message))
   IPC_END_MESSAGE_MAP()
 
   return true;
 }
 
 #if defined(OS_WIN)
 void GpuProcessHost::OnAcceleratedSurfaceCreatedChildWindow(
     gpu::SurfaceHandle parent_handle,
     gpu::SurfaceHandle window_handle) {
@@ skipping 258 matching lines @@
   urls_with_live_offscreen_contexts_.erase(url);
 }
 
 void GpuProcessHost::OnGpuMemoryUmaStatsReceived(
     const gpu::GPUMemoryUmaStats& stats) {
   TRACE_EVENT0("gpu", "GpuProcessHost::OnGpuMemoryUmaStatsReceived");
   uma_memory_stats_received_ = true;
   uma_memory_stats_ = stats;
 }
 
+void GpuProcessHost::OnFieldTrialActivated(const std::string& trial_name) {
+  // Activate the trial in the browser process to match its state in the
+  // GPU process. This is done by calling FindFullName which finalizes the group
+  // and activates the trial.
+  base::FieldTrialList::FindFullName(trial_name);
+}
+
 void GpuProcessHost::OnProcessLaunched() {
   UMA_HISTOGRAM_TIMES("GPU.GPUProcessLaunchTime",
                       base::TimeTicks::Now() - init_start_time_);
 }
 
 void GpuProcessHost::OnProcessLaunchFailed(int error_code) {
   // TODO(wfh): do something more useful with this error code.
   RecordProcessCrash();
 }
 
@@ skipping 251 matching lines @@
   TRACE_EVENT0("gpu", "GpuProcessHost::OnCacheShader");
   ClientIdToShaderCacheMap::iterator iter =
       client_id_to_shader_cache_.find(client_id);
   // If the cache doesn't exist then this is an off the record profile.
   if (iter == client_id_to_shader_cache_.end())
     return;
   iter->second->Cache(GetShaderPrefixKey() + ":" + key, shader);
 }
 
 }  // namespace content