Precache tracking database

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 f335cdf74bb2f4146a848774cf2056530c3ad0fd..1bbc165ff0bdf86bbe1c608d4eb1679b7f7fef49 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -13096,6 +13096,56 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Precache.DailyDownloadedKB" units="KB">
+  <summary>
+    The daily number of kilobytes that were downloaded during user browsing over
+    any network.
+  </summary>
+</histogram>
+
+<histogram name="Precache.DailyDownloadedKB.Cellular" units="KB">
+  <summary>
+    The daily number of kilobytes that were downloaded during user browsing over
+    a cellular network.
+  </summary>
+</histogram>
+
+<histogram name="Precache.DailyPrecachedKB" units="KB">
+  <summary>
+    The daily number of kilobytes that were downloaded while precaching.
+  </summary>
+</histogram>
+
+<histogram name="Precache.DailySavedKB" units="KB">
+  <summary>
+    The daily number of kilobytes during user browsing that were served from the
+    cache, but would have been downloaded over a network if precaching was
+    disabled.
+  </summary>
+</histogram>
+
+<histogram name="Precache.DailySavedKB.Cellular" units="KB">
+  <summary>
+    The daily number of kilobytes during user browsing that were served from the
+    cache, but would have been downloaded over a cellular network if precaching
+    was disabled.
+  </summary>
+</histogram>
+
+<histogram name="Precache.DailySavingsPercentage" units="%">
+  <summary>
+    The daily percentage of user browsing bandwidth on any network that was
+    saved because of precaching.
+  </summary>
+</histogram>
+
+<histogram name="Precache.DailySavingsPercentage.Cellular" units="%">
+  <summary>
+    The daily percentage of user browsing bandwidth on cellular networks that
+    was saved because of precaching.
+  </summary>
+</histogram>
+
 <histogram name="Prerender.Events" enum="PrerenderHoverEvent">
   <obsolete>
     deprecated May 10 2012
@@ -29721,6 +29771,18 @@ other types of suffix sets.
   <affected-histogram name="Plugin.PpapiPluginLoadResult"/>
 </fieldtrial>
 
+<fieldtrial name="Precache">
+  <group name="PrecacheEnabled" label="Precache is enabled."/>
+  <group name="PrecacheControl" label="Precache is disabled."/>
+  <affected-histogram name="Precache.DailyDownloadedKB"/>
+  <affected-histogram name="Precache.DailyDownloadedKB.Cellular"/>
+  <affected-histogram name="Precache.DailyPrecachedKB"/>
+  <affected-histogram name="Precache.DailySavedKB"/>
+  <affected-histogram name="Precache.DailySavedKB.Cellular"/>
+  <affected-histogram name="Precache.DailySavingsPercentage"/>
+  <affected-histogram name="Precache.DailySavingsPercentage.Cellular"/>
+</fieldtrial>
+
 <fieldtrial name="Prefetch">
   <group name="ContentPrefetchPrefetchOff"
       label="Prefetch is completely disabled."/>