[Android] Move zoom controls management into WebView

Chrome for Android doesn't use zoom controls, so it makes sense
to move all the related code into android_webview.

However, as visibility of zoom controls is controlled from the
internals of ContentView*, we are providing hooks through a new
delegate interface.

BUG=b/8296421
R=benm@chromium.org, joth@chromium.org

Review URL: https://codereview.chromium.org/14840011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@198862 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 284 insertions, 342 deletions

diff --git a/android_webview/java/src/org/chromium/android_webview/AwContents.java b/android_webview/java/src/org/chromium/android_webview/AwContents.java
index 4118f49..683304f 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -115,6 +115,7 @@ public class AwContents {
     private InterceptNavigationDelegateImpl mInterceptNavigationDelegate;
     private InternalAccessDelegate mInternalAccessAdapter;
     private final AwLayoutSizer mLayoutSizer;
+    private AwZoomControls mZoomControls;
     // This can be accessed on any thread after construction. See AwContentsIoThreadClient.
     private final AwSettings mSettings;
     private boolean mIsPaused;
@@ -328,12 +329,15 @@ public class AwContents {
         mCleanupReference = new CleanupReference(this, new DestroyRunnable(mNativeAwContents));
 
         int nativeWebContents = nativeGetWebContents(mNativeAwContents);
-        mContentViewCore.initialize(containerView, internalAccessAdapter, nativeWebContents, null);
+        mContentViewCore.initialize(
+                containerView, internalAccessAdapter, nativeWebContents, null);
         mContentViewCore.setContentViewClient(mContentsClient.getContentViewClient());
+        mZoomControls = new AwZoomControls(this);
+        mContentViewCore.setZoomControlsDelegate(mZoomControls);
         mContentsClient.installWebContentsObserver(mContentViewCore);
 
         mSettings = new AwSettings(mContentViewCore.getContext(), nativeWebContents,
-                isAccessFromFileURLsGrantedByDefault);
+                mContentViewCore, isAccessFromFileURLsGrantedByDefault);
         setIoThreadClient(new IoThreadClientImpl());
         setInterceptNavigationDelegate(new InterceptNavigationDelegateImpl());
 
@@ -573,11 +577,9 @@ public class AwContents {
                 ContentViewCore.PERSONALITY_VIEW);
         newCore.initialize(mContainerView, mInternalAccessAdapter, newWebContentsPtr, null);
         newCore.setContentViewClient(mContentsClient.getContentViewClient());
+        newCore.setZoomControlsDelegate(mZoomControls);
         mContentsClient.installWebContentsObserver(newCore);
 
-        ContentSettings oldSettings = mContentViewCore.getContentSettings();
-        newCore.getContentSettings().initFrom(oldSettings);
-
         // Now swap the Java side reference.
         mContentViewCore.destroy();
         mContentViewCore = newCore;
@@ -610,6 +612,14 @@ public class AwContents {
         }
     }
 
+    public boolean isMultiTouchZoomSupported() {
+        return mSettings.supportsMultiTouchZoom();
+    }
+
+    public View getZoomControlsForTest() {
+        return mZoomControls.getZoomControlsViewForTest();
+    }
+
     //--------------------------------------------------------------------------------------------
     //  WebView[Provider] method implementations (where not provided by ContentViewCore)
     //--------------------------------------------------------------------------------------------
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 8d1c57c7..cd8c484 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwSettings.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwSettings.java
@@ -17,6 +17,7 @@ import android.webkit.WebView;
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 import org.chromium.base.ThreadUtils;
+import org.chromium.content.browser.ContentViewCore;
 
 /**
  * Stores Android WebView specific settings that does not need to be synced to WebKit.
@@ -89,6 +90,9 @@ public class AwSettings {
     private int mCacheMode = WebSettings.LOAD_DEFAULT;
     private boolean mShouldFocusFirstNode = true;
     private boolean mGeolocationEnabled = true;
+    private boolean mSupportZoom = true;
+    private boolean mBuiltInZoomControls = false;
+    private boolean mDisplayZoomControls = true;
     static class LazyDefaultUserAgent{
         // Lazy Holder pattern
         private static final String sInstance = nativeGetDefaultUserAgent();
@@ -104,6 +108,8 @@ public class AwSettings {
     // The native side of this object.
     private int mNativeAwSettings = 0;
 
+    private ContentViewCore mContentViewCore;
+
     // A flag to avoid sending superfluous synchronization messages.
     private boolean mIsUpdateWebkitPrefsMessagePending = false;
     // Custom handler that queues messages to call native code on the UI thread.
@@ -159,7 +165,9 @@ public class AwSettings {
         }
     }
 
-    public AwSettings(Context context, int nativeWebContents,
+    public AwSettings(Context context,
+            int nativeWebContents,
+            ContentViewCore contentViewCore,
             boolean isAccessFromFileURLsGrantedByDefault) {
         ThreadUtils.assertOnUiThread();
         mContext = context;
@@ -169,6 +177,8 @@ public class AwSettings {
                 Process.myUid()) != PackageManager.PERMISSION_GRANTED;
         mNativeAwSettings = nativeInit(nativeWebContents);
         assert mNativeAwSettings != 0;
+        mContentViewCore = contentViewCore;
+        mContentViewCore.updateMultiTouchZoomSupport(supportsMultiTouchZoomLocked());
 
         if (isAccessFromFileURLsGrantedByDefault) {
             mAllowUniversalAccessFromFileURLs = true;
@@ -1059,6 +1069,91 @@ public class AwSettings {
         }
     }
 
+    private void updateMultiTouchZoomSupport(final boolean supportsMultiTouchZoom) {
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                mContentViewCore.updateMultiTouchZoomSupport(supportsMultiTouchZoom);
+            }
+        });
+    }
+
+    /**
+     * See {@link android.webkit.WebSettings#setSupportZoom}.
+     */
+    public void setSupportZoom(boolean support) {
+        synchronized (mAwSettingsLock) {
+            if (mSupportZoom != support) {
+                mSupportZoom = support;
+                updateMultiTouchZoomSupport(supportsMultiTouchZoomLocked());
+            }
+        }
+    }
+
+    /**
+     * 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;
+                updateMultiTouchZoomSupport(supportsMultiTouchZoomLocked());
+            }
+        }
+    }
+
+    /**
+     * See {@link android.webkit.WebSettings#getBuiltInZoomControls}.
+     */
+    public boolean getBuiltInZoomControls() {
+        synchronized (mAwSettingsLock) {
+            return mBuiltInZoomControls;
+        }
+    }
+
+    /**
+     * See {@link android.webkit.WebSettings#setDisplayZoomControls}.
+     */
+    public void setDisplayZoomControls(boolean enabled) {
+        synchronized (mAwSettingsLock) {
+            mDisplayZoomControls = enabled;
+        }
+    }
+
+    /**
+     * See {@link android.webkit.WebSettings#getDisplayZoomControls}.
+     */
+    public boolean getDisplayZoomControls() {
+        synchronized (mAwSettingsLock) {
+            return mDisplayZoomControls;
+        }
+    }
+
+    private boolean supportsMultiTouchZoomLocked() {
+        return mSupportZoom && mBuiltInZoomControls;
+    }
+
+    boolean supportsMultiTouchZoom() {
+        synchronized (mAwSettingsLock) {
+            return supportsMultiTouchZoomLocked();
+        }
+    }
+
+    boolean shouldDisplayZoomControls() {
+        synchronized (mAwSettingsLock) {
+            return supportsMultiTouchZoomLocked() && mDisplayZoomControls;
+        }
+    }
+
     private int clipFontSize(int size) {
         if (size < MINIMUM_FONT_SIZE) {
             return MINIMUM_FONT_SIZE;
diff --git a/android_webview/java/src/org/chromium/android_webview/AwZoomControls.java b/android_webview/java/src/org/chromium/android_webview/AwZoomControls.java
new file mode 100644
index 0000000..0bcae18
--- /dev/null
+++ b/android_webview/java/src/org/chromium/android_webview/AwZoomControls.java
@@ -0,0 +1,102 @@
+// Copyright (c) 2013 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.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.ZoomButtonsController;
+import org.chromium.content.browser.ContentViewCore.ZoomControlsDelegate;
+
+class AwZoomControls implements ZoomControlsDelegate {
+
+    private AwContents mAwContents;
+    // It is advised to use getZoomController() where possible.
+    private ZoomButtonsController mZoomButtonsController;
+
+    AwZoomControls(AwContents awContents) {
+        mAwContents = awContents;
+    }
+
+    @Override
+    public void invokeZoomPicker() {
+        ZoomButtonsController zoomController = getZoomController();
+        if (zoomController != null) {
+            zoomController.setVisible(true);
+        }
+    }
+
+    @Override
+    public void dismissZoomPicker() {
+        ZoomButtonsController zoomController = getZoomController();
+        if (zoomController != null) {
+            zoomController.setVisible(false);
+        }
+    }
+
+    @Override
+    public void updateZoomControls() {
+        ZoomButtonsController zoomController = getZoomController();
+        if (zoomController == null) {
+            return;
+        }
+        boolean canZoomIn = mAwContents.canZoomIn();
+        boolean canZoomOut = mAwContents.canZoomOut();
+        if (!canZoomIn && !canZoomOut) {
+            // Hide the zoom in and out buttons if the page cannot zoom
+            zoomController.getZoomControls().setVisibility(View.GONE);
+        } else {
+            // Set each one individually, as a page may be able to zoom in or out
+            zoomController.setZoomInEnabled(canZoomIn);
+            zoomController.setZoomOutEnabled(canZoomOut);
+        }
+    }
+
+    // This method is used in tests. It doesn't modify the state of zoom controls.
+    View getZoomControlsViewForTest() {
+        return mZoomButtonsController != null ? mZoomButtonsController.getZoomControls() : null;
+    }
+
+    private ZoomButtonsController getZoomController() {
+        if (mZoomButtonsController == null &&
+            mAwContents.getSettings().shouldDisplayZoomControls()) {
+            mZoomButtonsController = new ZoomButtonsController(
+                    mAwContents.getContentViewCore().getContainerView());
+            mZoomButtonsController.setOnZoomListener(new ZoomListener());
+            // ZoomButtonsController positions the buttons at the bottom, but in
+            // the middle. Change their layout parameters so they appear on the
+            // right.
+            View controls = mZoomButtonsController.getZoomControls();
+            ViewGroup.LayoutParams params = controls.getLayoutParams();
+            if (params instanceof FrameLayout.LayoutParams) {
+                ((FrameLayout.LayoutParams) params).gravity = Gravity.RIGHT;
+            }
+        }
+        return mZoomButtonsController;
+    }
+
+    private class ZoomListener implements ZoomButtonsController.OnZoomListener {
+        @Override
+        public void onVisibilityChanged(boolean visible) {
+            if (visible) {
+                // Bring back the hidden zoom controls.
+                mZoomButtonsController.getZoomControls().setVisibility(View.VISIBLE);
+                updateZoomControls();
+            }
+        }
+
+        @Override
+        public void onZoom(boolean zoomIn) {
+            if (zoomIn) {
+                mAwContents.zoomIn();
+            } else {
+                mAwContents.zoomOut();
+            }
+            // ContentView will call updateZoomControls after its current page scale
+            // is got updated from the native code.
+        }
+    }
+}
diff --git a/android_webview/javatests/src/org/chromium/android_webview/test/ContentViewZoomTest.java b/android_webview/javatests/src/org/chromium/android_webview/test/AwZoomTest.java
index c50d6f5..db46d07 100644
--- a/android_webview/javatests/src/org/chromium/android_webview/test/ContentViewZoomTest.java
+++ b/android_webview/javatests/src/org/chromium/android_webview/test/AwZoomTest.java
@@ -14,8 +14,6 @@ import org.chromium.android_webview.AwContents;
 import org.chromium.android_webview.AwSettings;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.Feature;
-import org.chromium.content.browser.ContentSettings;
-import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content.browser.test.util.Criteria;
 import org.chromium.content.browser.test.util.CriteriaHelper;
 
@@ -24,13 +22,12 @@ import java.util.concurrent.Callable;
 /**
  * A test suite for zooming-related methods and settings.
  */
-public class ContentViewZoomTest extends AwTestBase {
+public class AwZoomTest extends AwTestBase {
     private static final long TEST_TIMEOUT_MS = 20000L;
     private static final int CHECK_INTERVAL_MS = 100;
 
     private TestAwContentsClient mContentsClient;
     private AwContents mAwContents;
-    private ContentViewCore mContentViewCore;
 
     @Override
     public void setUp() throws Exception {
@@ -39,7 +36,6 @@ public class ContentViewZoomTest extends AwTestBase {
         final AwTestContainerView testContainerView =
                 createAwTestContainerViewOnMainSync(mContentsClient);
         mAwContents = testContainerView.getAwContents();
-        mContentViewCore = testContainerView.getContentViewCore();
     }
 
     private String getZoomableHtml() {
@@ -62,7 +58,7 @@ public class ContentViewZoomTest extends AwTestBase {
         return runTestOnUiThreadAndGetResult(new Callable<Boolean>() {
             @Override
             public Boolean call() throws Exception {
-                return mContentViewCore.isMultiTouchZoomSupported();
+                return mAwContents.isMultiTouchZoomSupported();
             }
         });
     }
@@ -80,7 +76,7 @@ public class ContentViewZoomTest extends AwTestBase {
         return runTestOnUiThreadAndGetResult(new Callable<Boolean>() {
             @Override
             public Boolean call() throws Exception {
-                return mContentViewCore.canZoomIn();
+                return mAwContents.canZoomIn();
             }
         });
     }
@@ -89,7 +85,7 @@ public class ContentViewZoomTest extends AwTestBase {
         return runTestOnUiThreadAndGetResult(new Callable<Boolean>() {
             @Override
             public Boolean call() throws Exception {
-                return mContentViewCore.canZoomOut();
+                return mAwContents.canZoomOut();
             }
         });
     }
@@ -98,7 +94,7 @@ public class ContentViewZoomTest extends AwTestBase {
         return runTestOnUiThreadAndGetResult(new Callable<Float>() {
             @Override
             public Float call() throws Exception {
-                return mContentViewCore.getScale();
+                return mAwContents.getScale();
             }
         });
     }
@@ -107,7 +103,7 @@ public class ContentViewZoomTest extends AwTestBase {
         return runTestOnUiThreadAndGetResult(new Callable<View>() {
             @Override
             public View call() throws Exception {
-                return mContentViewCore.getZoomControlsForTest();
+                return mAwContents.getZoomControlsForTest();
             }
         });
     }
@@ -116,7 +112,7 @@ public class ContentViewZoomTest extends AwTestBase {
         ThreadUtils.runOnUiThreadBlocking(new Runnable() {
             @Override
             public void run() {
-                mContentViewCore.invokeZoomPicker();
+                mAwContents.invokeZoomPicker();
             }
         });
     }
@@ -126,7 +122,7 @@ public class ContentViewZoomTest extends AwTestBase {
         if (!runTestOnUiThreadAndGetResult(new Callable<Boolean>() {
             @Override
             public Boolean call() throws Exception {
-                return mContentViewCore.zoomIn();
+                return mAwContents.zoomIn();
             }
            }))
             return false;
@@ -139,7 +135,7 @@ public class ContentViewZoomTest extends AwTestBase {
         if (!runTestOnUiThreadAndGetResult(new Callable<Boolean>() {
             @Override
             public Boolean call() throws Exception {
-                return mContentViewCore.zoomOut();
+                return mAwContents.zoomOut();
             }
            }))
             return false;
@@ -182,7 +178,7 @@ public class ContentViewZoomTest extends AwTestBase {
         loadDataSync(mAwContents, mContentsClient.getOnPageFinishedHelper(),
                 getZoomableHtml(), "text/html", false);
         mContentsClient.getOnScaleChangedHelper().waitForCallback(onScaleChangedCallCount);
-        getContentSettingsOnUiThread(mAwContents).setSupportZoom(supportZoom);
+        getAwSettingsOnUiThread(mAwContents).setSupportZoom(supportZoom);
         assertTrue("Should be able to zoom in", canZoomInOnUiThread());
         assertFalse("Should not be able to zoom out", canZoomOutOnUiThread());
 
@@ -218,14 +214,14 @@ public class ContentViewZoomTest extends AwTestBase {
         loadDataSync(mAwContents, mContentsClient.getOnPageFinishedHelper(),
                 getZoomableHtml(), "text/html", false);
 
-        assertTrue(getContentSettingsOnUiThread(mAwContents).supportZoom());
-        assertFalse(getContentSettingsOnUiThread(mAwContents).getBuiltInZoomControls());
+        assertTrue(webSettings.supportZoom());
+        assertFalse(webSettings.getBuiltInZoomControls());
         assertFalse(isMultiTouchZoomSupportedOnUiThread());
 
-        getContentSettingsOnUiThread(mAwContents).setBuiltInZoomControls(true);
+        webSettings.setBuiltInZoomControls(true);
         assertTrue(isMultiTouchZoomSupportedOnUiThread());
 
-        getContentSettingsOnUiThread(mAwContents).setSupportZoom(false);
+        webSettings.setSupportZoom(false);
         assertFalse(isMultiTouchZoomSupportedOnUiThread());
     }
 
@@ -240,9 +236,9 @@ public class ContentViewZoomTest extends AwTestBase {
         // It must be possible to zoom in (or zoom out) for zoom controls to be shown
         assertTrue("Should be able to zoom in", canZoomInOnUiThread());
 
-        assertTrue(getContentSettingsOnUiThread(mAwContents).supportZoom());
-        getContentSettingsOnUiThread(mAwContents).setBuiltInZoomControls(true);
-        getContentSettingsOnUiThread(mAwContents).setDisplayZoomControls(false);
+        assertTrue(webSettings.supportZoom());
+        webSettings.setBuiltInZoomControls(true);
+        webSettings.setDisplayZoomControls(false);
 
         // With DisplayZoomControls set to false, attempts to display zoom
         // controls must be ignored.
@@ -250,7 +246,7 @@ public class ContentViewZoomTest extends AwTestBase {
         invokeZoomPickerOnUiThread();
         assertNull(getZoomControlsOnUiThread());
 
-        getContentSettingsOnUiThread(mAwContents).setDisplayZoomControls(true);
+        webSettings.setDisplayZoomControls(true);
         assertNull(getZoomControlsOnUiThread());
         invokeZoomPickerOnUiThread();
         View zoomControls = getZoomControlsOnUiThread();
@@ -267,9 +263,9 @@ public class ContentViewZoomTest extends AwTestBase {
         // ContentView must update itself according to the viewport setup.
         waitUntilCanNotZoom();
 
-        assertTrue(getContentSettingsOnUiThread(mAwContents).supportZoom());
-        getContentSettingsOnUiThread(mAwContents).setBuiltInZoomControls(true);
-        getContentSettingsOnUiThread(mAwContents).setDisplayZoomControls(true);
+        assertTrue(webSettings.supportZoom());
+        webSettings.setBuiltInZoomControls(true);
+        webSettings.setDisplayZoomControls(true);
         assertNull(getZoomControlsOnUiThread());
         invokeZoomPickerOnUiThread();
         View zoomControls = getZoomControlsOnUiThread();
@@ -283,9 +279,9 @@ public class ContentViewZoomTest extends AwTestBase {
         loadDataSync(mAwContents, mContentsClient.getOnPageFinishedHelper(),
                 getZoomableHtml(), "text/html", false);
 
-        assertTrue(getContentSettingsOnUiThread(mAwContents).supportZoom());
-        getContentSettingsOnUiThread(mAwContents).setBuiltInZoomControls(true);
-        getContentSettingsOnUiThread(mAwContents).setDisplayZoomControls(true);
+        assertTrue(webSettings.supportZoom());
+        webSettings.setBuiltInZoomControls(true);
+        webSettings.setDisplayZoomControls(true);
         invokeZoomPickerOnUiThread();
 
         // Now force an orientation change, and try to display the zoom picker
diff --git a/build/android/findbugs_filter/findbugs_known_bugs.txt b/build/android/findbugs_filter/findbugs_known_bugs.txt
index c0fe27f..3533af4 100644
--- a/build/android/findbugs_filter/findbugs_known_bugs.txt
+++ b/build/android/findbugs_filter/findbugs_known_bugs.txt
@@ -27,7 +27,6 @@ M D DMI: Hard coded reference to an absolute pathname in org.chromium.android_we
 M D DMI: Hard coded reference to an absolute pathname in org.chromium.android_webview.test.ArchiveTest.testExplicitBadPath()  At ArchiveTest.java
 M D SF: Switch statement found in org.chromium.chrome.browser.ChromeBrowserProvider.insert(Uri, ContentValues) where one case falls through to the next case  At ChromeBrowserProvider.java
 M D SF: Switch statement found in org.chromium.chrome.browser.database.SQLiteCursor.fillWindow(int, CursorWindow) where default case is missing  At SQLiteCursor.java
-M D SF: Switch statement found in org.chromium.content.browser.ContentSettings$EventHandler$1.handleMessage(Message) where default case is missing  At ContentSettings.java
 M D SF: Switch statement found in org.chromium.content.browser.third_party.GestureDetector.onTouchEvent(MotionEvent) where default case is missing  At GestureDetector.java
 M M LI: Incorrect lazy initialization and update of static field org.chromium.content.browser.ContentVideoView.sContentVideoView in org.chromium.content.browser.ContentVideoView.createContentVideoView(int)  At ContentVideoView.java
 M M UG: org.chromium.content.browser.JavaBridgeReturnValuesTest$TestObject.getBooleanValue() is unsynchronized, org.chromium.content.browser.JavaBridgeReturnValuesTest$TestObject.setBooleanValue(boolean) is synchronized  At JavaBridgeReturnValuesTest.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentSettings.java b/content/public/android/java/src/org/chromium/content/browser/ContentSettings.java
index df03f00..d3ca0c6 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentSettings.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentSettings.java
@@ -4,78 +4,25 @@
 
 package org.chromium.content.browser;
 
-import android.os.Handler;
-import android.os.Looper;
-import android.os.Message;
-
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 import org.chromium.base.ThreadUtils;
 
-import java.util.concurrent.Callable;
-
 /**
  * Manages settings state for a ContentView. A ContentSettings instance is obtained
- * from ContentView.getContentSettings(). If ContentView is used in the
- * ContentView.PERSONALITY_VIEW role, all settings are read / write. If ContentView
- * is in the ContentView.PERSONALITY_CHROME role, setting can only be read.
+ * from ContentViewCore.getContentSettings().
  */
 @JNINamespace("content")
 public class ContentSettings {
 
     private static final String TAG = "ContentSettings";
 
-    // This class must be created on the UI thread. Afterwards, it can be
-    // used from any thread. Internally, the class uses a message queue
-    // to call native code on the UI thread only.
-
     // The native side of this object. Ownership is retained native-side by the WebContents
     // instance that backs the associated ContentViewCore.
     private int mNativeContentSettings = 0;
 
     private ContentViewCore mContentViewCore;
 
-    // Custom handler that queues messages to call native code on the UI thread.
-    private final EventHandler mEventHandler;
-
-    // Protects access to settings fields.
-    private final Object mContentSettingsLock = new Object();
-
-    private boolean mSupportZoom = true;
-    private boolean mBuiltInZoomControls = false;
-    private boolean mDisplayZoomControls = true;
-
-    // Class to handle messages to be processed on the UI thread.
-    private class EventHandler {
-        // Message id for updating multi-touch zoom state in the view
-        private static final int UPDATE_MULTI_TOUCH = 2;
-        // Actual UI thread handler
-        private Handler mHandler;
-
-        EventHandler() {
-            if (mContentViewCore.isPersonalityView()) {
-                mHandler = new Handler(Looper.getMainLooper()) {
-                    @Override
-                    public void handleMessage(Message msg) {
-                        switch (msg.what) {
-                            case UPDATE_MULTI_TOUCH:
-                                if (mContentViewCore.isAlive()) {
-                                    mContentViewCore.updateMultiTouchZoomSupport();
-                                }
-                                break;
-                        }
-                    }
-                };
-            }
-        }
-
-        private void sendUpdateMultiTouchMessageLocked() {
-            assert Thread.holdsLock(mContentSettingsLock);
-            if (mNativeContentSettings == 0) return;
-            mHandler.sendMessage(Message.obtain(null, UPDATE_MULTI_TOUCH));
-        }
-    }
-
     /**
      * Package constructor to prevent clients from creating a new settings
      * instance. Must be called on the UI thread.
@@ -85,12 +32,6 @@ public class ContentSettings {
         mContentViewCore = contentViewCore;
         mNativeContentSettings = nativeInit(nativeContentView);
         assert mNativeContentSettings != 0;
-
-        mEventHandler = new EventHandler();
-        if (!mContentViewCore.isPersonalityView()) {
-            mBuiltInZoomControls = true;
-            mDisplayZoomControls = false;
-        }
     }
 
     /**
@@ -104,126 +45,14 @@ public class ContentSettings {
     }
 
     /**
-     * Sets whether the WebView should support zooming using its on-screen zoom
-     * controls and gestures. The particular zoom mechanisms that should be used
-     * can be set with {@link #setBuiltInZoomControls}. This setting does not
-     * affect zooming performed using the {@link WebView#zoomIn()} and
-     * {@link WebView#zoomOut()} methods. The default is true.
-     *
-     * @param support whether the WebView should support zoom
-     */
-    public void setSupportZoom(boolean support) {
-        synchronized (mContentSettingsLock) {
-            mSupportZoom = support;
-            mEventHandler.sendUpdateMultiTouchMessageLocked();
-        }
-    }
-
-    /**
-     * Gets whether the WebView supports zoom.
-     *
-     * @return true if the WebView supports zoom
-     * @see #setSupportZoom
-     */
-    public boolean supportZoom() {
-        return mSupportZoom;
-    }
-
-   /**
-     * Sets whether the WebView should use its built-in zoom mechanisms. The
-     * built-in zoom mechanisms comprise on-screen zoom controls, which are
-     * displayed over the WebView's content, and the use of a pinch gesture to
-     * control zooming. Whether or not these on-screen controls are displayed
-     * can be set with {@link #setDisplayZoomControls}. The default is false,
-     * due to compatibility reasons.
-     * <p>
-     * The built-in mechanisms are the only currently supported zoom
-     * mechanisms, so it is recommended that this setting is always enabled.
-     * In other words, there is no point of calling this method other than
-     * with the 'true' parameter.
-     *
-     * @param enabled whether the WebView should use its built-in zoom mechanisms
-     */
-     public void setBuiltInZoomControls(boolean enabled) {
-        synchronized (mContentSettingsLock) {
-            mBuiltInZoomControls = enabled;
-            mEventHandler.sendUpdateMultiTouchMessageLocked();
-        }
-    }
-
-    /**
-     * Gets whether the zoom mechanisms built into WebView are being used.
-     *
-     * @return true if the zoom mechanisms built into WebView are being used
-     * @see #setBuiltInZoomControls
-     */
-    public boolean getBuiltInZoomControls() {
-        return mBuiltInZoomControls;
-    }
-
-    /**
-     * Sets whether the WebView should display on-screen zoom controls when
-     * using the built-in zoom mechanisms. See {@link #setBuiltInZoomControls}.
-     * The default is true.
-     *
-     * @param enabled whether the WebView should display on-screen zoom controls
-     */
-    public void setDisplayZoomControls(boolean enabled) {
-        synchronized (mContentSettingsLock) {
-            mDisplayZoomControls = enabled;
-            mEventHandler.sendUpdateMultiTouchMessageLocked();
-        }
-    }
-
-    /**
-     * Gets whether the WebView displays on-screen zoom controls when using
-     * the built-in zoom mechanisms.
-     *
-     * @return true if the WebView displays on-screen zoom controls when using
-     *         the built-in zoom mechanisms
-     * @see #setDisplayZoomControls
-     */
-    public boolean getDisplayZoomControls() {
-        return mDisplayZoomControls;
-    }
-
-    boolean supportsMultiTouchZoom() {
-        return mSupportZoom && mBuiltInZoomControls;
-    }
-
-    boolean shouldDisplayZoomControls() {
-        return supportsMultiTouchZoom() && mDisplayZoomControls;
-    }
-
-    /**
-     * Return true if JavaScript is enabled.
+     * Return true if JavaScript is enabled. Must be called on the UI thread.
      *
      * @return True if JavaScript is enabled.
      */
     public boolean getJavaScriptEnabled() {
-        return ThreadUtils.runOnUiThreadBlockingNoException(new Callable<Boolean>() {
-                @Override
-                public Boolean call() {
-                    if (mNativeContentSettings != 0) {
-                        return nativeGetJavaScriptEnabled(mNativeContentSettings);
-                    } else {
-                        return false;
-                    }
-                }
-            });
-    }
-
-    /**
-     * Sets the settings in this object to those from another
-     * ContentSettings.
-     * Required by WebView when we swap a in a new ContentViewCore
-     * to an existing AwContents (i.e. to support displaying popup
-     * windows in an already created WebView)
-     */
-    public void initFrom(ContentSettings settings) {
-        setSupportZoom(settings.supportZoom());
-        setBuiltInZoomControls(settings.getBuiltInZoomControls());
-        setDisplayZoomControls(settings.getDisplayZoomControls());
+        ThreadUtils.assertOnUiThread();
+        return mNativeContentSettings != 0 ?
+                nativeGetJavaScriptEnabled(mNativeContentSettings) : false;
     }
 
     // Initialize the ContentSettings native side.
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentView.java b/content/public/android/java/src/org/chromium/content/browser/ContentView.java
index 9ea4fb4..ae00c5b 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentView.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentView.java
@@ -635,14 +635,6 @@ public class ContentView extends FrameLayout
         mContentViewCore.onVisibilityChanged(changedView, visibility);
     }
 
-    void updateMultiTouchZoomSupport() {
-        mContentViewCore.updateMultiTouchZoomSupport();
-    }
-
-    public boolean isMultiTouchZoomSupported() {
-        return mContentViewCore.isMultiTouchZoomSupported();
-    }
-
     /**
      * Register the delegate to be used when content can not be handled by
      * the rendering engine, and should be downloaded instead. This will replace
@@ -742,17 +734,6 @@ public class ContentView extends FrameLayout
         return mContentViewCore.zoomReset();
     }
 
-    // Invokes the graphical zoom picker widget for this ContentView.
-    public void invokeZoomPicker() {
-        mContentViewCore.invokeZoomPicker();
-    }
-
-    // Unlike legacy WebView getZoomControls which returns external zoom controls,
-    // this method returns built-in zoom controls. This method is used in tests.
-    public View getZoomControlsForTest() {
-        return mContentViewCore.getZoomControlsForTest();
-    }
-
     /**
      * Return the current scale of the WebView
      * @return The current scale.
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 88375d7..62a4693 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
@@ -119,7 +119,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
      * implementing container view.
      */
     @SuppressWarnings("javadoc")
-    public static interface InternalAccessDelegate {
+    public interface InternalAccessDelegate {
         /**
          * @see View#drawChild(Canvas, View, long)
          */
@@ -170,7 +170,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
      * An interface that allows the embedder to be notified when the pinch gesture starts and
      * stops.
      */
-    public static interface PinchGestureStateListener {
+    public interface PinchGestureStateListener {
         /**
          * Called when the pinch gesture starts.
          */
@@ -181,6 +181,24 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
         void onPinchGestureEnd();
     }
 
+    /**
+     * An interface for controlling visibility and state of embedder-provided zoom controls.
+     */
+    public interface ZoomControlsDelegate {
+        /**
+         * Called when it's reasonable to show zoom controls.
+         */
+        void invokeZoomPicker();
+        /**
+         * Called when zoom controls need to be hidden (e.g. when the view hides).
+         */
+        void dismissZoomPicker();
+        /**
+         * Called when page scale has been changed, so the controls can update their state.
+         */
+        void updateZoomControls();
+    }
+
     private VSyncManager.Provider mVSyncProvider;
     private VSyncManager.Listener mVSyncListener;
     private int mVSyncSubscriberCount;
@@ -276,6 +294,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
     private ContentViewGestureHandler mContentViewGestureHandler;
     private PinchGestureStateListener mPinchGestureStateListener;
     private ZoomManager mZoomManager;
+    private ZoomControlsDelegate mZoomControlsDelegate;
 
     private PopupZoomer mPopupZoomer;
 
@@ -655,8 +674,15 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
         }
 
         mZoomManager = new ZoomManager(mContext, this);
-        mZoomManager.updateMultiTouchSupport();
         mContentViewGestureHandler = new ContentViewGestureHandler(mContext, this, mZoomManager);
+        mZoomControlsDelegate = new ZoomControlsDelegate() {
+            @Override
+            public void invokeZoomPicker() {}
+            @Override
+            public void dismissZoomPicker() {}
+            @Override
+            public void updateZoomControls() {}
+        };
 
         mRenderCoordinates.reset();
 
@@ -1367,9 +1393,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
         }
         setAccessibilityState(false);
         hidePopupDialog();
-        if (mContentSettings != null && mContentSettings.supportZoom()) {
-            mZoomManager.dismissZoomPicker();
-        }
+        mZoomControlsDelegate.dismissZoomPicker();
     }
 
     /**
@@ -1377,9 +1401,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
      */
     public void onVisibilityChanged(View changedView, int visibility) {
       if (visibility != View.VISIBLE) {
-          if (mContentSettings.supportZoom()) {
-              mZoomManager.dismissZoomPicker();
-          }
+          mZoomControlsDelegate.dismissZoomPicker();
       }
     }
 
@@ -1781,12 +1803,12 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
         }
     }
 
-    void updateMultiTouchZoomSupport() {
-        mZoomManager.updateMultiTouchSupport();
+    public void setZoomControlsDelegate(ZoomControlsDelegate zoomControlsDelegate) {
+        mZoomControlsDelegate = zoomControlsDelegate;
     }
 
-    public boolean isMultiTouchZoomSupported() {
-        return mZoomManager.isMultiTouchZoomSupported();
+    public void updateMultiTouchZoomSupport(boolean supportsMultiTouchZoom) {
+        mZoomManager.updateMultiTouchSupport(supportsMultiTouchZoom);
     }
 
     public void selectPopupMenuItems(int[] indices) {
@@ -2160,7 +2182,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
                 contentOffsetYPix);
 
         if (needTemporarilyHideHandles) temporarilyHideTextHandles();
-        if (needUpdateZoomControls) mZoomManager.updateZoomControls();
+        if (needUpdateZoomControls) mZoomControlsDelegate.updateZoomControls();
         if (contentOffsetChanged) updateHandleScreenPositions();
 
         // Update offsets for fullscreen.
@@ -2445,15 +2467,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
      */
     @Override
     public void invokeZoomPicker() {
-        if (mContentSettings != null && mContentSettings.supportZoom()) {
-            mZoomManager.invokeZoomPicker();
-        }
-    }
-
-    // Unlike legacy WebView getZoomControls which returns external zoom controls,
-    // this method returns built-in zoom controls. This method is used in tests.
-    public View getZoomControlsForTest() {
-        return mZoomManager.getZoomControlsViewForTest();
+        mZoomControlsDelegate.invokeZoomPicker();
     }
 
     /**
diff --git a/content/public/android/java/src/org/chromium/content/browser/ZoomManager.java b/content/public/android/java/src/org/chromium/content/browser/ZoomManager.java
index 8e8df31..986d61e 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ZoomManager.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ZoomManager.java
@@ -6,23 +6,17 @@ package org.chromium.content.browser;
 
 import android.content.Context;
 import android.util.Log;
-import android.view.Gravity;
 import android.view.MotionEvent;
 import android.view.ScaleGestureDetector;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.FrameLayout;
-import android.widget.ZoomButtonsController;
 
 /**
- * The ZoomManager is responsible for maintaining the ContentView's current zoom
- * level state. It is also responsible for managing the on-screen zoom controls.
+ * ZoomManager is responsible for maintaining the ContentView's current zoom
+ * level state and process scaling-related gestures.
  */
 class ZoomManager {
     private static final String TAG = "ContentViewZoom";
 
     private ContentViewCore mContentViewCore;
-    private ZoomButtonsController mZoomButtonsController;
 
     private class ScaleGestureListener implements ScaleGestureDetector.OnScaleGestureListener {
         // Completely silence scaling events. Used in WebView when zoom support
@@ -102,26 +96,8 @@ class ZoomManager {
         mMultiTouchDetector = new ScaleGestureDetector(context, mMultiTouchListener);
     }
 
-    void invokeZoomPicker() {
-        ZoomButtonsController zoomControls = getZoomControls();
-        if (zoomControls != null && !zoomControls.isVisible()) {
-            zoomControls.setVisible(true);
-        }
-    }
-
-    void dismissZoomPicker() {
-        ZoomButtonsController zoomControls = getZoomControls();
-        if (zoomControls != null && zoomControls.isVisible()) {
-            zoomControls.setVisible(false);
-        }
-    }
-
-    boolean isMultiTouchZoomSupported() {
-        return !mMultiTouchListener.getPermanentlyIgnoreDetectorEvents();
-    }
-
     boolean isScaleGestureDetectionInProgress() {
-        return isMultiTouchZoomSupported()
+        return !mMultiTouchListener.getPermanentlyIgnoreDetectorEvents()
                 && mMultiTouchDetector.isInProgress();
     }
 
@@ -156,67 +132,7 @@ class ZoomManager {
         return false;
     }
 
-    void updateMultiTouchSupport() {
-        mMultiTouchListener.setPermanentlyIgnoreDetectorEvents(
-            !mContentViewCore.getContentSettings().supportsMultiTouchZoom());
-    }
-
-    private ZoomButtonsController getZoomControls() {
-        if (mZoomButtonsController == null &&
-            mContentViewCore.getContentSettings().shouldDisplayZoomControls()) {
-            mZoomButtonsController = new ZoomButtonsController(
-                    mContentViewCore.getContainerView());
-            mZoomButtonsController.setOnZoomListener(new ZoomListener());
-            // ZoomButtonsController positions the buttons at the bottom, but in
-            // the middle. Change their layout parameters so they appear on the
-            // right.
-            View controls = mZoomButtonsController.getZoomControls();
-            ViewGroup.LayoutParams params = controls.getLayoutParams();
-            if (params instanceof FrameLayout.LayoutParams) {
-                ((FrameLayout.LayoutParams) params).gravity = Gravity.RIGHT;
-            }
-        }
-        return mZoomButtonsController;
-    }
-
-    // This method is used in tests. It doesn't modify the state of zoom controls.
-    View getZoomControlsViewForTest() {
-        return mZoomButtonsController != null ? mZoomButtonsController.getZoomControls() : null;
-    }
-
-    void updateZoomControls() {
-        if (mZoomButtonsController == null) return;
-        boolean canZoomIn = mContentViewCore.canZoomIn();
-        boolean canZoomOut = mContentViewCore.canZoomOut();
-        if (!canZoomIn && !canZoomOut) {
-            // Hide the zoom in and out buttons if the page cannot zoom
-            mZoomButtonsController.getZoomControls().setVisibility(View.GONE);
-        } else {
-            // Set each one individually, as a page may be able to zoom in or out
-            mZoomButtonsController.setZoomInEnabled(canZoomIn);
-            mZoomButtonsController.setZoomOutEnabled(canZoomOut);
-        }
-    }
-
-    private class ZoomListener implements ZoomButtonsController.OnZoomListener {
-        @Override
-        public void onVisibilityChanged(boolean visible) {
-            if (visible) {
-                // Bring back the hidden zoom controls.
-                mZoomButtonsController.getZoomControls().setVisibility(View.VISIBLE);
-                updateZoomControls();
-            }
-        }
-
-        @Override
-        public void onZoom(boolean zoomIn) {
-            if (zoomIn) {
-                mContentViewCore.zoomIn();
-            } else {
-                mContentViewCore.zoomOut();
-            }
-            // ContentView will call updateZoomControls after its current page scale
-            // is got updated from the native code.
-        }
+    void updateMultiTouchSupport(boolean supportsMultiTouchZoom) {
+        mMultiTouchListener.setPermanentlyIgnoreDetectorEvents(!supportsMultiTouchZoom);
     }
 }