Do not wait for the double tap timeout on pages with fixed page scale

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.util.Log;
 import android.util.Pair;
@@ skipping 180 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();
+
+        /**
+         * @return Whether changing the page scale is not possible on the current page.
+         */
+        public boolean hasFixedPageScale();
     }
 
     ContentViewGestureHandler(
             Context context, MotionEventDelegate delegate, ZoomManager zoomManager) {
         mExtraParamBundle = new Bundle();
         mLongPressDetector = new LongPressDetector(context, this);
         mMotionEventDelegate = delegate;
         mZoomManager = zoomManager;
         initGestureDetectors(context);
     }
@@ skipping 173 matching lines @@
                         if (!mIgnoreSingleTap && !mLongPressDetector.isInLongPress() &&
                                 (e.getEventTime() - e.getDownTime() > DOUBLE_TAP_TIMEOUT)) {
                             float x = e.getX();
                             float y = e.getY();
                             if (mMotionEventDelegate.sendGesture(GESTURE_SINGLE_TAP_UP,
                                     e.getEventTime(), (int) x, (int) y, null)) {
                                 mIgnoreSingleTap = true;
                             }
                             setClickXAndY((int) x, (int) y);
                             return true;
+                        } else if (mMotionEventDelegate.hasFixedPageScale()) {
+                            // If page is not user scalable, we don't need to wait
+                            // for double tap timeout.
+                            float x = e.getX();
+                            float y = e.getY();
+                            mExtraParamBundle.clear();
+                            mExtraParamBundle.putBoolean(SHOW_PRESS, mShowPressIsCalled);
+                            if (mMotionEventDelegate.sendGesture(GESTURE_SINGLE_TAP_CONFIRMED,
+                                    e.getEventTime(), (int) x, (int) y, mExtraParamBundle)) {
+                                mIgnoreSingleTap = true;
+                            }
+                            setClickXAndY((int) x, (int) y);
                         }
                         return false;
                     }
 
                     @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.
@@ skipping 339 matching lines @@
     /**
      * @return Whether the ContentViewGestureHandler can handle a MotionEvent right now. True only
      * if it's the start of a new stream (ACTION_DOWN), or a continuation of the current stream.
      */
     boolean canHandle(MotionEvent ev) {
         return ev.getAction() == MotionEvent.ACTION_DOWN ||
                 (mCurrentDownEvent != null && mCurrentDownEvent.getDownTime() == ev.getDownTime());
     }
 
 }