Added UMA stat for tracking accidental navigations on double tap.

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java

Index: content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
index 739a66ab7a2fb0074f31d921dd8aa60857e11c7b..3ac3579096dbff959879458f5bc9e6f05169082a 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
@@ -459,6 +459,18 @@ public class ContentViewCore
 
     private ViewAndroid mViewAndroid;
 
+    public static class UMAActionAfterDoubleTap {
+        public static final int NAVIGATE_BACK = 0;
+        public static final int NAVIGATE_STOP = 1;
+        public static final int NO_ACTION = 2;
+        public static final int COUNT = 3;
+    }
+
+    public static class UMASingleTapType {
+        public static final int DELAYED_TAP = 0;
+        public static final int UNDELAYED_TAP = 1;
+        public static final int COUNT = 2;
+    }
 
     /**
      * Constructs a new ContentViewCore. Embedders must call initialize() after constructing
@@ -1323,6 +1335,10 @@ public class ContentViewCore
         }
     }
 
+    public void reportActionAfterDoubleTapUMA(int type) {

[Ted C, 2013/11/07 04:26:08]

based on my other comment in TabBase, hopefully this can become private

[bokan, 2013/11/07 06:26:42]

Done.

+        mContentViewGestureHandler.reportActionAfterDoubleTapUMA(type);
+    }
+
     @Override
     public boolean sendGesture(int type, long timeMs, int x, int y, Bundle b) {
         if (offerGestureToEmbedder(type)) return false;
@@ -1394,6 +1410,24 @@ public class ContentViewCore
     }
 
     @Override
+    public void sendSingleTapUMA(int type) {
+        nativeSendSingleTapUma(

[Ted C, 2013/11/07 04:26:08]

probably worth a check like:
if (mNativeContentViewCore == 0) return;

There are some weird lifetime issues with WebView, so probably best to be
consistent and handle things dying underneath us.

[bokan, 2013/11/07 06:26:42]

Done.

+                mNativeContentViewCore,
+                type,
+                UMASingleTapType.COUNT);
+    }
+
+    @Override
+    public void sendActionAfterDoubleTapUMA(int type,
+            boolean clickDelayEnabled) {
+        nativeSendActionAfterDoubleTapUma(
+                mNativeContentViewCore,
+                type,
+                clickDelayEnabled,
+                UMAActionAfterDoubleTap.COUNT);
+    }
+
+    @Override
     public void onSentLastGestureForVSync(long eventTimeMs) {
         if (isVSyncNotificationEnabled()) {
             mDidSignalVSyncUsingInputEvent = true;
@@ -3375,4 +3409,10 @@ public class ContentViewCore
 
     private native void nativeSetAccessibilityEnabled(
             int nativeContentViewCoreImpl, boolean enabled);
+
+    private native void nativeSendSingleTapUma(int nativeContentViewCoreImpl,
+            int type, int count);
+
+    private native void nativeSendActionAfterDoubleTapUma(int nativeContentViewCoreImpl,
+            int type, boolean hasDelay, int count);
 }