Plugin Power Saver: Refactor some Tiny plugin code and tests.

content/renderer/pepper/plugin_power_saver_helper.cc

Index: content/renderer/pepper/plugin_power_saver_helper.cc
diff --git a/content/renderer/pepper/plugin_power_saver_helper.cc b/content/renderer/pepper/plugin_power_saver_helper.cc
index 6776f46b207fa6cb1abd5d69f2a968d277ca2a37..21f69cd30b290e8a5feec3406e70a03f0cacbaef 100644
--- a/content/renderer/pepper/plugin_power_saver_helper.cc
+++ b/content/renderer/pepper/plugin_power_saver_helper.cc
@@ -112,9 +112,9 @@ PluginPowerSaverHelper::GetPeripheralContentStatus(
   auto status = PeripheralContentHeuristic::GetPeripheralStatus(
       origin_whitelist_, main_frame_origin, content_origin, unobscured_size);
 
-  // Never record ESSENTIAL_UNKNOWN_SIZE. Wait for retest after size is known.
+  // Never record UNKNOWN_SIZE. Wait for retest after size is known.
   if (record_decision == RenderFrame::RECORD_DECISION &&
-      status != RenderFrame::CONTENT_STATUS_ESSENTIAL_UNKNOWN_SIZE) {
+      status != RenderFrame::CONTENT_STATUS_UNKNOWN_SIZE) {
     UMA_HISTOGRAM_ENUMERATION(kPeripheralHeuristicHistogram, status,
                               RenderFrame::CONTENT_STATUS_NUM_ITEMS);
   }