Implement Virtual Display class for Android.

ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java

Index: ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java
diff --git a/ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java b/ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java
index 6175f940303e80ee9df4afbc5c65cb358a2d988d..e6bb8eb5329aa1eff984a14038fd3685699fbe2a 100644
--- a/ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java
+++ b/ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java
@@ -112,7 +112,7 @@ import org.chromium.ui.gfx.DeviceDisplayInfo;
         @Override
         public void onConfigurationChanged(Configuration newConfig) {
             updateDeviceDisplayInfo();
-            mIdMap.get(mMainSdkDisplayId).updateFromDisplay(
+            ((DisplayAndroidImpl) mIdMap.get(mMainSdkDisplayId)).updateFromDisplay(
                     getDefaultDisplayForContext(getContext()));
         }
 
@@ -171,7 +171,7 @@ import org.chromium.ui.gfx.DeviceDisplayInfo;
         @Override
         public void onDisplayChanged(int sdkDisplayId) {
             updateDeviceDisplayInfo();
-            DisplayAndroid displayAndroid = mIdMap.get(sdkDisplayId);
+            DisplayAndroidImpl displayAndroid = (DisplayAndroidImpl) mIdMap.get(sdkDisplayId);
             if (displayAndroid != null) {
                 displayAndroid.updateFromDisplay(getDisplayManager().getDisplay(sdkDisplayId));
             }
@@ -278,13 +278,25 @@ import org.chromium.ui.gfx.DeviceDisplayInfo;
 
     private DisplayAndroid addDisplay(Display display) {
         int sdkDisplayId = display.getDisplayId();
-        DisplayAndroid displayAndroid = new DisplayAndroid(display);
+        DisplayAndroidImpl displayAndroid = new DisplayAndroidImpl(display);
         mIdMap.put(sdkDisplayId, displayAndroid);
 
         displayAndroid.updateFromDisplay(display);
         return displayAndroid;
     }
 
+    /* package */ void addVirtualDisplay(VirtualDisplayAndroid display) {
+        mIdMap.put(display.getSdkDisplayId(), display);
+    }
+
+    /* package */ void removeVirtualDisplay(VirtualDisplayAndroid display) {
+        DisplayAndroid displayAndroid = mIdMap.get(display.getSdkDisplayId());
+        assert displayAndroid == display;
+
+        if (mNativePointer != 0) nativeRemoveDisplay(mNativePointer, display.getSdkDisplayId());
+        mIdMap.remove(display.getSdkDisplayId());
+    }
+
     /* package */ void updateDisplayOnNativeSide(DisplayAndroid displayAndroid) {
         if (mNativePointer == 0) return;
         nativeUpdateDisplay(mNativePointer, displayAndroid.getSdkDisplayId(),