[Android] Add mechanism to disable double tap/drag zooming.

android_webview/java/src/org/chromium/android_webview/AwSettings.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.android_webview;
 
 import android.content.Context;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
@@ skipping 151 matching lines @@
                 try {
                     while (mIsUpdateWebkitPrefsMessagePending) {
                         mAwSettingsLock.wait();
                     }
                 } catch (InterruptedException e) {}
             }
         }
     }
 
     interface ZoomSupportChangeListener {
-        public void onMultiTouchZoomSupportChanged(boolean supportsMultiTouchZoom);
+        public void onGestureZoomSupportChanged(boolean supportsGestureZoom);
     }
 
     public AwSettings(Context context, boolean hasInternetPermission,
             ZoomSupportChangeListener zoomChangeListener,
             boolean isAccessFromFileURLsGrantedByDefault,
             double dipScale) {
         ThreadUtils.assertOnUiThread();
         synchronized (mAwSettingsLock) {
             mHasInternetPermission = hasInternetPermission;
             mZoomChangeListener = zoomChangeListener;
             mDIPScale = dipScale;
             mEventHandler = new EventHandler();
             mBlockNetworkLoads = !hasInternetPermission;
 
             if (isAccessFromFileURLsGrantedByDefault) {
                 mAllowUniversalAccessFromFileURLs = true;
                 mAllowFileAccessFromFileURLs = true;
             }
 
             mUserAgent = LazyDefaultUserAgent.sInstance;
-            onMultiTouchZoomSupportChanged(supportsMultiTouchZoomLocked());
+            onGestureZoomSupportChanged(supportsGestureZoomLocked());
 
             // Respect the system setting for password echoing.
             mPasswordEchoEnabled = Settings.System.getInt(context.getContentResolver(),
                     Settings.System.TEXT_SHOW_PASSWORD, 1) == 1;
         }
         // Defer initializing the native side until a native WebContents instance is set.
     }
 
     @CalledByNative
     private void nativeAwSettingsGone(int nativeAwSettings) {
@@ skipping 1038 matching lines @@
         synchronized (mAwSettingsLock) {
             return mDefaultVideoPosterURL;
         }
     }
 
     @CalledByNative
     private String getDefaultVideoPosterURLLocked() {
         return mDefaultVideoPosterURL;
     }
 
-    private void onMultiTouchZoomSupportChanged(final boolean supportsMultiTouchZoom) {
+    private void onGestureZoomSupportChanged(final boolean supportsGestureZoom) {
         // Always post asynchronously here, to avoid doubling back onto the caller.
         ThreadUtils.postOnUiThread(new Runnable() {
             @Override
             public void run() {
-                mZoomChangeListener.onMultiTouchZoomSupportChanged(supportsMultiTouchZoom);
+                mZoomChangeListener.onGestureZoomSupportChanged(supportsGestureZoom);
             }
         });
     }
 
     /**
      * See {@link android.webkit.WebSettings#setSupportZoom}.
      */
     public void setSupportZoom(boolean support) {
         synchronized (mAwSettingsLock) {
             if (mSupportZoom != support) {
                 mSupportZoom = support;
-                onMultiTouchZoomSupportChanged(supportsMultiTouchZoomLocked());
+                onGestureZoomSupportChanged(supportsGestureZoomLocked());
             }
         }
     }
 
     /**
      * See {@link android.webkit.WebSettings#supportZoom}.
      */
     public boolean supportZoom() {
         synchronized (mAwSettingsLock) {
             return mSupportZoom;
         }
     }
 
     /**
      * See {@link android.webkit.WebSettings#setBuiltInZoomControls}.
      */
     public void setBuiltInZoomControls(boolean enabled) {
         synchronized (mAwSettingsLock) {
             if (mBuiltInZoomControls != enabled) {
                 mBuiltInZoomControls = enabled;
-                onMultiTouchZoomSupportChanged(supportsMultiTouchZoomLocked());
+                onGestureZoomSupportChanged(supportsGestureZoomLocked());
             }
         }
     }
 
     /**
      * See {@link android.webkit.WebSettings#getBuiltInZoomControls}.
      */
     public boolean getBuiltInZoomControls() {
         synchronized (mAwSettingsLock) {
             return mBuiltInZoomControls;
@@ skipping 11 matching lines @@
 
     /**
      * See {@link android.webkit.WebSettings#getDisplayZoomControls}.
      */
     public boolean getDisplayZoomControls() {
         synchronized (mAwSettingsLock) {
             return mDisplayZoomControls;
         }
     }
 
-    private boolean supportsMultiTouchZoomLocked() {
+    private boolean supportsGestureZoomLocked() {
         assert Thread.holdsLock(mAwSettingsLock);
         return mSupportZoom && mBuiltInZoomControls;
     }
 
-    boolean supportsMultiTouchZoom() {
+    boolean supportsGestureZoom() {
         synchronized (mAwSettingsLock) {
-            return supportsMultiTouchZoomLocked();
+            return supportsGestureZoomLocked();
         }
     }
 
     boolean shouldDisplayZoomControls() {
         synchronized (mAwSettingsLock) {
-            return supportsMultiTouchZoomLocked() && mDisplayZoomControls;
+            return supportsGestureZoomLocked() && mDisplayZoomControls;
         }
     }
 
     private int clipFontSize(int size) {
         if (size < MINIMUM_FONT_SIZE) {
             return MINIMUM_FONT_SIZE;
         } else if (size > MAXIMUM_FONT_SIZE) {
             return MAXIMUM_FONT_SIZE;
         }
         return size;
@@ skipping 24 matching lines @@
     private native void nativeUpdateInitialPageScaleLocked(int nativeAwSettings);
 
     private native void nativeUpdateUserAgentLocked(int nativeAwSettings);
 
     private native void nativeUpdateWebkitPreferencesLocked(int nativeAwSettings);
 
     private static native String nativeGetDefaultUserAgent();
 
     private native void nativeUpdateFormDataPreferencesLocked(int nativeAwSettings);
 }