Convert ChromeViewMsg_SetFieldTrialGroup to use mojo.

chrome/common/renderer_configuration.mojom

Index: chrome/common/renderer_configuration.mojom
diff --git a/chrome/common/renderer_configuration.mojom b/chrome/common/renderer_configuration.mojom
index 851167c743aba7cd62f0bb32fc96680069d4674b..276079ac513eee76aed5982c2d5e82c981281f82 100644
--- a/chrome/common/renderer_configuration.mojom
+++ b/chrome/common/renderer_configuration.mojom
@@ -15,4 +15,21 @@ interface RendererConfiguration {
   // Set the content setting rules stored by the renderer.
   SetContentSettingRules(
       content_settings.mojom.RendererContentSettingRules rules);
+
+  // Tells the renderer to create a FieldTrial, and by using a 100% probability
+  // for the FieldTrial, forces the FieldTrial to have assigned group name.
+  //
+  // Example trial_name / group_name pairs are:
+  //	- "BrowserScheduler" / "Default"
+  //	- "QUIC" / "Enabled"
+  //	- "SimpleCacheTrial" / "ExperimentYes"
+  //	- "WebFontsInterventionV2" / "Enabled-slow2g"
+  //	- "MarkNonSecureAs" / "show-non-secure-passwords-cc-ui"
+  SetFieldTrialGroup(string trial_name, string group_name);
+};
+
+// Records field trial activations from the renderers.
+interface FieldTrialRecorder {
+  // Indicates that a field trial has been activated.
+  FieldTrialActivated(string trial_name);
 };