Send all field trials from the browser.

chrome/browser/renderer_host/chrome_render_message_filter.cc

Index: chrome/browser/renderer_host/chrome_render_message_filter.cc
diff --git a/chrome/browser/renderer_host/chrome_render_message_filter.cc b/chrome/browser/renderer_host/chrome_render_message_filter.cc
index 2ffe311d8a31ae7032c17260eb12e6b8e4d9bda1..78860b50ed1c63ba99b6a24661c3693f43c22fab 100644
--- a/chrome/browser/renderer_host/chrome_render_message_filter.cc
+++ b/chrome/browser/renderer_host/chrome_render_message_filter.cc
@@ -8,6 +8,7 @@
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/content_settings/cookie_settings.h"
@@ -84,6 +85,8 @@ bool ChromeRenderMessageFilter::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_IsCrashReportingEnabled,
                         OnIsCrashReportingEnabled)
 #endif
+    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_FieldTrialActivated,
+                        OnFieldTrialActivated)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -363,3 +366,11 @@ void ChromeRenderMessageFilter::OnIsCrashReportingEnabled(bool* enabled) {
   *enabled = ChromeMetricsServiceAccessor::IsCrashReportingEnabled();
 }
 #endif
+
+void ChromeRenderMessageFilter::OnFieldTrialActivated(
+    const std::string& trial_name) {
+  // Activate the trial in the browser process to match its state in the
+  // renderer. This is done by calling FindFullName which finalizes the group
+  // and activates the trial.
+  base::FieldTrialList::FindFullName(trial_name);
+}