Make WebView work for external displays (over Presentations).

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

Index: content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
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 929e494039c791499ebb359716cf9526ab8b12d8..da3c9480df1091bbb5914156ef73c833a237ae86 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
@@ -601,6 +601,9 @@ public class ContentViewCore implements
     // The client that implements Contextual Search functionality, or null if none exists.
     private ContextualSearchClient mContextualSearchClient;
 
+    // Listener for screen orientation changes.
+    private ScreenOrientationListener mScreenOrientationListener;
+
     /**
      * @param webContents The {@link WebContents} to find a {@link ContentViewCore} of.
      * @return            A {@link ContentViewCore} that is connected to {@code webContents} or
@@ -639,6 +642,7 @@ public class ContentViewCore implements
         mEditable = Editable.Factory.getInstance().newEditable("");
         Selection.setSelection(mEditable, 0);
         mContainerViewObservers = new ObserverList<ContainerViewObserver>();
+        mScreenOrientationListener = new ScreenOrientationListener(mContext);
     }
 
     /**
@@ -1002,7 +1006,7 @@ public class ContentViewCore implements
         mRetainedJavaScriptObjects.clear();
         unregisterAccessibilityContentObserver();
         mGestureStateListeners.clear();
-        ScreenOrientationListener.getInstance().removeObserver(this);
+        mScreenOrientationListener.removeObserver(this);
         mPositionObserver.clearListener();
         mContainerViewObservers.clear();
 
@@ -1493,7 +1497,7 @@ public class ContentViewCore implements
         setAccessibilityState(mAccessibilityManager.isEnabled());
         setTextHandlesTemporarilyHidden(false);
         restoreSelectionPopupsIfNecessary();
-        ScreenOrientationListener.getInstance().addObserver(this, mContext);
+        mScreenOrientationListener.addObserver(this);
         GamepadList.onAttachedToWindow(mContext);
         mAccessibilityManager.addAccessibilityStateChangeListener(this);
         mSystemCaptioningBridge.addListener(this);
@@ -1508,7 +1512,7 @@ public class ContentViewCore implements
         mZoomControlsDelegate.dismissZoomPicker();
         unregisterAccessibilityContentObserver();
 
-        ScreenOrientationListener.getInstance().removeObserver(this);
+        mScreenOrientationListener.removeObserver(this);
         GamepadList.onDetachedFromWindow();
         mAccessibilityManager.removeAccessibilityStateChangeListener(this);