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

android_webview/java/src/org/chromium/android_webview/AwSettings.java

Index: android_webview/java/src/org/chromium/android_webview/AwSettings.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwSettings.java b/android_webview/java/src/org/chromium/android_webview/AwSettings.java
index b62cc4d5a6151e0d19cff164c4a571b3398a52e4..eea28987e69855155c5f4ebc91121089816f1459 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwSettings.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwSettings.java
@@ -169,7 +169,7 @@ public class AwSettings {
     }
 
     interface ZoomSupportChangeListener {
-        public void onMultiTouchZoomSupportChanged(boolean supportsMultiTouchZoom);
+        public void onGestureZoomSupportChanged(boolean supportsGestureZoom);
     }
 
     public AwSettings(Context context, boolean hasInternetPermission,
@@ -190,7 +190,7 @@ public class AwSettings {
             }
 
             mUserAgent = LazyDefaultUserAgent.sInstance;
-            onMultiTouchZoomSupportChanged(supportsMultiTouchZoomLocked());
+            onGestureZoomSupportChanged(supportsGestureZoomLocked());
 
             // Respect the system setting for password echoing.
             mPasswordEchoEnabled = Settings.System.getInt(context.getContentResolver(),
@@ -1249,12 +1249,12 @@ public class AwSettings {
         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);
             }
         });
     }
@@ -1266,7 +1266,7 @@ public class AwSettings {
         synchronized (mAwSettingsLock) {
             if (mSupportZoom != support) {
                 mSupportZoom = support;
-                onMultiTouchZoomSupportChanged(supportsMultiTouchZoomLocked());
+                onGestureZoomSupportChanged(supportsGestureZoomLocked());
             }
         }
     }
@@ -1287,7 +1287,7 @@ public class AwSettings {
         synchronized (mAwSettingsLock) {
             if (mBuiltInZoomControls != enabled) {
                 mBuiltInZoomControls = enabled;
-                onMultiTouchZoomSupportChanged(supportsMultiTouchZoomLocked());
+                onGestureZoomSupportChanged(supportsGestureZoomLocked());
             }
         }
     }
@@ -1319,20 +1319,20 @@ public class AwSettings {
         }
     }
 
-    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;
         }
     }