Adds histograms for casting feature of Video Player

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 6eb000374e759bbc24614eb4b827e01ee1ec245b..657bd13298199b11b180a2333a3d85e5cd440ffc 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -39229,6 +39229,53 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="VideoPlayer.CastedVideoLength">

[Ilya Sherman, 2014/12/02 23:45:10]

nit: Please add a units attribute.

[yoshiki, 2014/12/08 02:52:29]

Done.

+  <owner>yoshiki@chromium.org</owner>
+  <summary>
+    Chrome OS Video Player: the length of casted video (in seconds).
+  </summary>
+</histogram>
+
+<histogram name="VideoPlayer.CastExtensionStatus"
+    enum="VideoPlayerCastExtensionStatus">
+  <owner>yoshiki@chromium.org</owner>
+  <summary>
+    Chrome OS Video Player: the statuses of the cast extension and the cast API
+    extension.
+  </summary>
+</histogram>
+
+<histogram name="VideoPlayer.CastVideo">
+  <owner>yoshiki@chromium.org</owner>
+  <summary>
+    Chrome OS Video Player: count the number of casted video files.
+  </summary>
+</histogram>
+
+<histogram name="VideoPlayer.CastVideoError">
+  <owner>yoshiki@chromium.org</owner>
+  <summary>Chrome OS Video Player: count the number of cast error.</summary>
+</histogram>
+
+<histogram name="VideoPlayer.NumberOfCastDevice">
+  <owner>yoshiki@chromium.org</owner>
+  <summary>Chrome OS Video Player: the number of cast devices.</summary>

[Ilya Sherman, 2014/12/02 23:45:10]

When is this recorded?

[yoshiki, 2014/12/08 02:52:29]

Added a comment in description.

+</histogram>
+
+<histogram name="VideoPlayer.NumberOfOpenedFile">
+  <owner>yoshiki@chromium.org</owner>
+  <summary>
+    Chrome OS Video Player: the number of files being opened on launch.
+  </summary>
+</histogram>
+
+<histogram name="VideoPlayer.OpenVideoPlayer">
+  <owner>yoshiki@chromium.org</owner>
+  <summary>
+    Chrome OS Video Player: this is recorded when user opens video player.
+  </summary>
+</histogram>
+
 <histogram name="Viewport.MetaTagType" enum="MetaTagTypeEnum">
   <owner>bokan@chromium.org</owner>
   <summary>
@@ -56724,6 +56771,16 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="7" label="YV12J"/>
 </enum>
 
+<enum name="VideoPlayerCastExtensionStatus" type="int">
+  <int value="0" label="Cast extension is unavailable."/>
+  <int value="1" label="Installation of Cast API extension is failed."/>
+  <int value="2" label="Load of Cast API extension is failed."/>
+  <int value="3"
+      label="Cast API extension is installed and loaded successfully."/>
+  <int value="4"
+      label="Cast API extension is available and loaded successfully."/>
+</enum>
+
 <enum name="VideoRotation" type="int">
   <int value="0" label="VIDEO_ROTATION_0"/>
   <int value="1" label="VIDEO_ROTATION_90"/>