Added UMA stat for tracking accidental navigations on double tap.

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.content.browser;
 
 import android.content.Context;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.SystemClock;
@@ skipping 319 matching lines @@
          * @param x The amount scrolled in the X direction.
          * @param y The amount scrolled in the Y direction.
          * @return Whether or not the UI consumed and handled this event.
          */
         boolean didUIStealScroll(float x, float y);
 
         /**
          * Show the zoom picker UI.
          */
         public void invokeZoomPicker();
+
+        /**
+         * Send action after dobule tap for UMA stat tracking

[Rick Byers, 2013/11/01 19:27:03]

nit - missing period here and below.

[Rick Byers, 2013/11/01 19:27:03]

nit - Looks like convention is to add javadoc comments for parameters, please
add here and below.

[bokan, 2013/11/01 19:54:02]

Done.

[bokan, 2013/11/01 19:54:02]

Done.

+         */
+        public void sendActionAfterDoubleTapUMA(
+                ContentViewCore.UMAActionAfterDoubleTap type,
+                boolean clickDelayEnabled);
+
+        /**
+         * Send single tap UMA
+         */
+        public void sendSingleTapUMA(ContentViewCore.UMASingleTapType type);
     }
 
     ContentViewGestureHandler(
             Context context, MotionEventDelegate delegate, ZoomManager zoomManager,
             int inputEventDeliveryMode) {
         mExtraParamBundleSingleTap = new Bundle();
         mExtraParamBundleFling = new Bundle();
         mExtraParamBundleScroll = new Bundle();
         mExtraParamBundleDoubleTapDragZoom = new Bundle();
         mExtraParamBundlePinchBy = new Bundle();
@@ skipping 175 matching lines @@
                     }
 
                     @Override
                     public boolean onSingleTapConfirmed(MotionEvent e) {
                         // Long taps in the edges of the screen have their events delayed by
                         // ContentViewHolder for tab swipe operations. As a consequence of the delay
                         // this method might be called after receiving the up event.
                         // These corner cases should be ignored.
                         if (mLongPressDetector.isInLongPress() || mIgnoreSingleTap) return true;
 
+                        if (!isDoubleTapDisabled() && !mDisableClickDelay)
+                            mMotionEventDelegate.sendSingleTapUMA(

[Rick Byers, 2013/11/01 19:27:03]

nit - don't repeat the call to the function, just make the parameter be
conditional (inline or with a local variable).  Eg:
isDoubleTapDisabled || mDisableClickDelay ? UNDELAYED_TAP : DELAYED_TAP;

[bokan, 2013/11/01 19:54:02]

Done.

+                                    ContentViewCore.UMASingleTapType.DELAYED_TAP);
+                        else
+                            mMotionEventDelegate.sendSingleTapUMA(
+                                    ContentViewCore.UMASingleTapType.UNDELAYED_TAP);
+
                         int x = (int) e.getX();
                         int y = (int) e.getY();
                         mExtraParamBundleSingleTap.putBoolean(SHOW_PRESS, mShowPressIsCalled);
                         assert mExtraParamBundleSingleTap.size() == 1;
                         if (sendMotionEventAsGesture(GESTURE_SINGLE_TAP_CONFIRMED, e,
                                 mExtraParamBundleSingleTap)) {
                             mIgnoreSingleTap = true;
                         }
 
                         setClickXAndY(x, y);
@@ skipping 585 matching lines @@
         mNoTouchHandlerForGesture = false;
         trySendPendingEventsToNative();
     }
 
     private void recycleEvent(MotionEvent event) {
         event.recycle();
     }
 
     private boolean sendMotionEventAsGesture(
             int type, MotionEvent event, Bundle extraParams) {
-        return mMotionEventDelegate.sendGesture(type, event.getEventTime(),
+        return sendGesture(type, event.getEventTime(),
             (int) event.getX(), (int) event.getY(), extraParams);
     }
 
     private boolean sendGesture(
             int type, long timeMs, int x, int y, Bundle extraParams) {
+        updateDoubleTapUmaTimer();
+
+        if (type == GESTURE_DOUBLE_TAP)
+            reportDoubleTap();
+
         return mMotionEventDelegate.sendGesture(type, timeMs, x, y, extraParams);
     }
 
     private boolean sendGestureAndRequestVSync(
             int type, long timeMs, int x, int y, Bundle extraParams) {
         // VSync should only be signalled if the sent gesture was generated from a touch event.
         mSentGestureNeedsVSync = mInputEventsDeliveredAtVSync && mTouchEventHandlingStackDepth > 0;
         mLastVSyncGestureTimeMs = timeMs;
-        return mMotionEventDelegate.sendGesture(type, timeMs, x, y, extraParams);
+        return sendGesture(type, timeMs, x, y, extraParams);
     }
 
     void sendShowPressCancelIfNecessary(MotionEvent e) {
         if (!mShowPressIsCalled) return;
 
         if (sendMotionEventAsGesture(GESTURE_SHOW_PRESS_CANCEL, e, null)) {
             mShowPressIsCalled = false;
             mLastLongPressEvent = null;
         }
     }
@@ skipping 95 matching lines @@
     private void updateDoubleTapListener() {
         if (isDoubleTapDisabled()) {
             // Defer nulling the DoubleTapListener until the double tap gesture is complete.
             if (isDoubleTapActive()) return;
             mGestureDetector.setOnDoubleTapListener(null);
         } else {
             mGestureDetector.setOnDoubleTapListener(mDoubleTapListener);
         }
 
     }
+
+    public void reportDoubleTap() {
+        // Make sure repeated double taps don't get silently dropped from
+        // the statistics.
+        if (mLastDoubleTapTimeMs > 0)
+            mMotionEventDelegate.sendActionAfterDoubleTapUMA(
+                    ContentViewCore.UMAActionAfterDoubleTap.NO_ACTION,
+                    !mDisableClickDelay);
+
+        mLastDoubleTapTimeMs = SystemClock.uptimeMillis();
+    }
+
+    public void reportActionAfterDoubleTapUMA(
+            ContentViewCore.UMAActionAfterDoubleTap type) {
+        updateDoubleTapUmaTimer();
+
+        if (mLastDoubleTapTimeMs == 0)
+            return;
+
+        long nowMs = SystemClock.uptimeMillis();
+        if ((nowMs - mLastDoubleTapTimeMs)
+                < ACTION_AFTER_DOUBLE_TAP_WINDOW_MS) {
+            mMotionEventDelegate.sendActionAfterDoubleTapUMA(
+                    type, !mDisableClickDelay);
+            mLastDoubleTapTimeMs = 0;
+        }
+    }
+
+    // Watch for the UMA "action after double tap" timer expiring and reset
+    // the timer if necessary.
+    private void updateDoubleTapUmaTimer() {
+        if (mLastDoubleTapTimeMs == 0)
+            return;
+
+        long nowMs = SystemClock.uptimeMillis();
+        if ((nowMs - mLastDoubleTapTimeMs)
+              >= ACTION_AFTER_DOUBLE_TAP_WINDOW_MS) {
+            // Time expired, user took no action (that we care about).
+            mMotionEventDelegate.sendActionAfterDoubleTapUMA(
+                    ContentViewCore.UMAActionAfterDoubleTap.NO_ACTION,
+                    !mDisableClickDelay);
+            mLastDoubleTapTimeMs = 0;
+        }
+    }
+
+    // Used for tracking UMA ActionAfterDoubleTap to tell user's immediate
+    // action after a double tap.
+    private long mLastDoubleTapTimeMs = 0;
+    private static final long ACTION_AFTER_DOUBLE_TAP_WINDOW_MS = 5000;
 }