Enable FeatureList for the GPU process.

content/browser/browser_child_process_host_impl.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/browser_child_process_host_impl.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/dump_without_crashing.h"
+#include "base/feature_list.h"
 #include "base/files/file_path.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/synchronization/waitable_event.h"
 #include "build/build_config.h"
 #include "components/tracing/tracing_switches.h"
 #include "content/browser/histogram_message_filter.h"
 #include "content/browser/loader/resource_message_filter.h"
 #include "content/browser/memory/memory_message_filter.h"
 #include "content/browser/profiler_message_filter.h"
@@ skipping 144 matching lines @@
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   // Make a copy since the BrowserChildProcessHost dtor mutates the original
   // list.
   BrowserChildProcessList copy = g_child_process_list.Get();
   for (BrowserChildProcessList::iterator it = copy.begin();
        it != copy.end(); ++it) {
     delete (*it)->delegate();  // ~*HostDelegate deletes *HostImpl.
   }
 }
 
+// static
+void BrowserChildProcessHostImpl::CopyFeatureAndFieldTrialFlags(
+    base::CommandLine* cmd_line) {
+  std::string enabled_features;
+  std::string disabled_features;
+  base::FeatureList::GetInstance()->GetFeatureOverrides(&enabled_features,
+                                                        &disabled_features);
+  if (!enabled_features.empty())
+    cmd_line->AppendSwitchASCII(switches::kEnableFeatures, enabled_features);
+  if (!disabled_features.empty())
+    cmd_line->AppendSwitchASCII(switches::kDisableFeatures, disabled_features);
+
+  // If we run base::FieldTrials, we want to pass to their state to the
+  // child process so that it can act in accordance with each state.
+  std::string field_trial_states;
+  base::FieldTrialList::AllStatesToString(&field_trial_states);
+  if (!field_trial_states.empty()) {
+    cmd_line->AppendSwitchASCII(switches::kForceFieldTrials,
+                                field_trial_states);
+  }
+}
+
 void BrowserChildProcessHostImpl::Launch(
     SandboxedProcessLauncherDelegate* delegate,
     base::CommandLine* cmd_line,
     bool terminate_on_shutdown) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   GetContentClient()->browser()->AppendExtraCommandLineSwitches(
       cmd_line, data_.id);
 
   const base::CommandLine& browser_command_line =
@@ skipping 246 matching lines @@
 
 #if defined(OS_WIN)
 
 void BrowserChildProcessHostImpl::OnObjectSignaled(HANDLE object) {
   OnChildDisconnected();
 }
 
 #endif
 
 }  // namespace content