Plugin Power Saver: Add Poster Param metric.

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 4e8128da5b10f95847e2fc6409757a637b13f19b..cd2c55fba6d31430de3e6b7d0bc3513276ea9cf1 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -26739,6 +26739,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Plugin.PowerSaver.PosterParamPresence"
+    enum="PluginPowerSaverPosterParamPresence">
+  <owner>tommycli@chromium.org</owner>
+  <summary>
+    Record how many plugin object tags use poster param. This is recorded once
+    per plugin instance, and is currently restricted to Flash plugin instances.
+  </summary>
+</histogram>
+
 <histogram name="Plugin.PowerSaver.Unthrottle"
     enum="PluginPowerSaverUnthrottleMethod">
   <owner>tommycli@chromium.org</owner>
@@ -55200,6 +55209,13 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="4" label="Essential Cross-Origin Tiny"/>
 </enum>
 
+<enum name="PluginPowerSaverPosterParamPresence" type="int">
+  <int value="0" label="No poster param. Plugin power saver disabled."/>
+  <int value="1" label="No poster param. Plugin power saver enabled."/>
+  <int value="2" label="Poster param exists. Plugin power saver disabled."/>
+  <int value="3" label="Poster param exists. Plugin power saver enabled."/>
+</enum>
+
 <enum name="PluginPowerSaverUnthrottleMethod" type="int">
   <int value="0" label="Never Unthrottled"/>
   <int value="1" label="Unthrottled by Click"/>