Reenable Purge+Suspend Memory Growth metrics.

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index b2734508a09094e420d8eba1d43fd6157f872dd1..4ea70173926dc2a8c96a491bf990404733fc3593 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -590,9 +590,14 @@ class CONTENT_EXPORT RenderThreadImpl
   void OnRendererHidden();
   void OnRendererVisible();
 
+  enum RecordMemoryGrowthTiming {
+    RECORD_30MIN_AFTER_PURGE,
+    RECORD_60MIN_AFTER_PURGE,
+    RECORD_90MIN_AFTER_PURGE
+  };
   void RecordPurgeAndSuspendMemoryGrowthMetrics(
-      const char* suffix,
-      int foregrounded_count_when_purged);
+      int foregrounded_count_when_purged,
+      RecordMemoryGrowthTiming record_timing);
 
   void ReleaseFreeMemory();