Plugin Power Saver: Make Unthrottle metric collection more consistent

content/renderer/pepper/plugin_instance_throttler_impl.cc

Index: content/renderer/pepper/plugin_instance_throttler_impl.cc
diff --git a/content/renderer/pepper/plugin_instance_throttler_impl.cc b/content/renderer/pepper/plugin_instance_throttler_impl.cc
index ea06846f786539c2979415a4d0873229e898008b..67440e16e5b190799f072b90db3f6d933c7e31ce 100644
--- a/content/renderer/pepper/plugin_instance_throttler_impl.cc
+++ b/content/renderer/pepper/plugin_instance_throttler_impl.cc
@@ -4,7 +4,6 @@
 
 #include "content/renderer/pepper/plugin_instance_throttler_impl.h"
 
-#include "base/metrics/histogram.h"
 #include "base/time/time.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/renderer/render_frame.h"
@@ -17,15 +16,6 @@ namespace content {
 
 namespace {
 
-const char kPowerSaverUnthrottleHistogram[] = "Plugin.PowerSaver.Unthrottle";
-
-void RecordUnthrottleMethodMetric(
-    PluginInstanceThrottlerImpl::PowerSaverUnthrottleMethod method) {
-  UMA_HISTOGRAM_ENUMERATION(
-      kPowerSaverUnthrottleHistogram, method,
-      PluginInstanceThrottler::UNTHROTTLE_METHOD_NUM_ITEMS);
-}
-
 // When we give up waiting for a suitable preview frame, and simply suspend
 // the plugin where it's at. In milliseconds.
 const int kThrottleTimeout = 5000;
@@ -64,6 +54,8 @@ PluginInstanceThrottlerImpl::PluginInstanceThrottlerImpl(
 }
 
 PluginInstanceThrottlerImpl::~PluginInstanceThrottlerImpl() {
+  if (state_ != PLUGIN_INSTANCE_MARKED_ESSENTIAL)
+    RecordUnthrottleMethodMetric(UNTHROTTLE_METHOD_NEVER);
 }
 
 void PluginInstanceThrottlerImpl::AddObserver(Observer* observer) {