Plugin Power Saver: Add some UMAs to test plugins in wild.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 33bef4a10a8d4a01c0939146a4f24d672ea7b984..e28a4bf2a614932388d62d64a37c0389b4ac44c9 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -25041,6 +25041,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>Collects Flash usage data.</summary>
 </histogram>
 
+<histogram name="Plugin.PowerSaverPeripheralHeuristic"
+    enum="PluginPowerSaverPeripheralHeuristicDecision">
+  <owner>tommycli@chromium.org</owner>
+  <summary>
+    Record initial decision of the Plugin Power Saver peripheral content
+    heuristic.
+  </summary>
+</histogram>
+
 <histogram name="Plugin.PpapiBrokerLoadErrorCode" units="code">
   <owner>xhwang@chromium.org</owner>
   <summary>The error code of a PPAPI broker load failure.</summary>
@@ -51078,6 +51087,13 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="4" label="FILE_MISSING"/>
 </enum>
 
+<enum name="PluginPowerSaverPeripheralHeuristicDecision" type="int">
+  <int value="0" label="Peripheral"/>
+  <int value="1" label="Essential Same-Origin"/>
+  <int value="2" label="Essential Cross-Origin Big"/>
+  <int value="3" label="Essential Cross-Origin Whitelisted"/>
+</enum>
+
 <enum name="PNaClOptionsOptLevelEnum" type="int">
   <int value="0" label="0"/>
   <int value="1" label="1"/>