Added UMA stat for tracking accidental navigations on double tap.

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 6a1961d47885f08227f44d481fd0415d107e8a0c..01be0ef3078d8291cc0ac10cd300de27b93eaeac 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -18775,6 +18775,20 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="UserInput.ActionAfterDoubleTapNoDelay" enum="UserAction">
+  <summary>
+    User's first action within 5 seconds after a double tap gesture when gesture
+    tap event delay is disabled.
+  </summary>
+</histogram>
+
+<histogram name="UserInput.ActionAfterDoubleTapWithDelay" enum="UserAction">
+  <summary>
+    User's first action within 5 seconds after a double tap gesture when gesture
+    tap events are delayed.
+  </summary>
+</histogram>
+
 <histogram name="UserManager.LoginUserType" enum="UserType">
   <summary>
     The number of users of different types that log in to the system (Chrome
@@ -28051,6 +28065,12 @@ other types of suffix sets.
   <int value="10" label="kFileSystemScheme"/>
 </enum>
 
+<enum name="UserAction" type="int">
+  <int value="0" label="Navigated Back"/>
+  <int value="1" label="Stopped Navigation"/>
+  <int value="2" label="No Action"/>
+</enum>
+
 <enum name="UserType" type="int">
   <int value="0" label="Regular"/>
   <int value="1" label="Guest"/>