Add UMA metric for tracking root level listeners for blocking touch.

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 3b0b4b595c240e49c2e02e834c2d66e5a0b24105..563b802ba6422387389acfd9888c0da82be61b2e 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -12386,6 +12386,20 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Event.Touch.TargetAndDispatchResult"
     enum="TouchTargetAndDispatchResultType">
+  <obsolete>
+    Deprecated 05/2016, and replaced by Event.Touch.TargetAndDispatchResult2.
+  </obsolete>
+  <owner>dtapuska@chromium.org</owner>
+  <summary>
+    An enumeration identifying 3 properties: 1) a classification of the event
+    target whether it is a root scroll listener (window, document, body) or not;
+    2) the result of the dispatch; 3) whether the document was scrollable or
+    not.
+  </summary>
+</histogram>
+
+<histogram name="Event.Touch.TargetAndDispatchResult2"
+    enum="TouchTargetAndDispatchResultType2">
   <owner>dtapuska@chromium.org</owner>
   <summary>
     An enumeration identifying 3 properties: 1) a classification of the event

[Rick Byers, 2016/05/19 16:30:51]

please update the histogram description to describe precisely what it's
measuring and when - we always get this confused when looking at the dashboard
:-)

[dtapuska, 2016/05/19 18:14:23]

Done.

@@ -88492,6 +88506,89 @@ To add a new entry, add it with any value and run test to compute valid value.
       label="Root-scroller, scrollable document, handled application"/>
 </enum>
 
+<enum name="TouchTargetAndDispatchResultType2" type="int">
+  <int value="0"
+      label="Capturing Non-root-scroller, non-scrollable document, already
+             handled"/>
+  <int value="1"
+      label="Capturing Non-root-scroller, non-scrollable document, not
+             handled"/>
+  <int value="2"
+      label="Capturing Non-root-scroller, non-scrollable document, handled
+             application"/>
+  <int value="3"
+      label="Capturing Non-root-scroller, scrollable document, already
+             handled"/>
+  <int value="4"
+      label="Capturing Non-root-scroller, scrollable document, not handled"/>
+  <int value="5"
+      label="Capturing Non-root-scroller, scrollable document, handled
+             application"/>
+  <int value="6"
+      label="Capturing Root-scroller, non-scrollable document, already
+             handled"/>
+  <int value="7"
+      label="Capturing Root-scroller, non-scrollable document, not handled"/>
+  <int value="8"
+      label="Capturing Root-scroller, non-scrollable document, handled
+             application"/>
+  <int value="9"
+      label="Capturing Root-scroller, scrollable document, already handled"/>
+  <int value="10"
+      label="Capturing Root-scroller, scrollable document, not handled"/>
+  <int value="11"
+      label="Capturing Root-scroller, scrollable document, handled
+             application"/>
+  <int value="12"
+      label="Non-root-scroller, non-scrollable document, already handled"/>
+  <int value="13"
+      label="Non-root-scroller, non-scrollable document, not handled"/>
+  <int value="14"
+      label="Non-root-scroller, non-scrollable document, handled application"/>
+  <int value="15"
+      label="Non-root-scroller, scrollable document, already handled"/>
+  <int value="16" label="Non-root-scroller, scrollable document, not handled"/>
+  <int value="17"
+      label="Non-root-scroller, scrollable document, handled application"/>
+  <int value="18"
+      label="Root-scroller, non-scrollable document, already handled"/>
+  <int value="19" label="Root-scroller, non-scrollable document, not handled"/>
+  <int value="20"
+      label="Root-scroller, non-scrollable document, handled application"/>
+  <int value="21" label="Root-scroller, scrollable document, already handled"/>
+  <int value="22" label="Root-scroller, scrollable document, not handled"/>
+  <int value="23"
+      label="Root-scroller, scrollable document, handled application"/>
+  <int value="24"
+      label="Bubbling Non-root-scroller, non-scrollable document, already
+             handled"/>
+  <int value="25"
+      label="Bubbling Non-root-scroller, non-scrollable document, not handled"/>
+  <int value="26"
+      label="Bubbling Non-root-scroller, non-scrollable document, handled
+             application"/>
+  <int value="27"
+      label="Bubbling Non-root-scroller, scrollable document, already handled"/>
+  <int value="28"
+      label="Bubbling Non-root-scroller, scrollable document, not handled"/>
+  <int value="29"
+      label="Bubbling Non-root-scroller, scrollable document, handled
+             application"/>
+  <int value="30"
+      label="Bubbling Root-scroller, non-scrollable document, already handled"/>
+  <int value="31"
+      label="Bubbling Root-scroller, non-scrollable document, not handled"/>
+  <int value="32"
+      label="Bubbling Root-scroller, non-scrollable document, handled
+             application"/>
+  <int value="33"
+      label="Bubbling Root-scroller, scrollable document, already handled"/>
+  <int value="34"
+      label="Bubbling Root-scroller, scrollable document, not handled"/>
+  <int value="35"
+      label="Bubbling Root-scroller, scrollable document, handled application"/>
+</enum>
+
 <enum name="TPMResultCodeEnum" type="int">
   <int value="0" label="TPM_SUCCESS"/>
   <int value="1" label="TPM_E_AUTHFAIL"/>