Introduce ViewRoot to forward input/view events to native

android_webview/java/src/org/chromium/android_webview/AwContents.java

Index: android_webview/java/src/org/chromium/android_webview/AwContents.java
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 27eb4f4671caab62bf63eaf8954ffd387a94503e..5e452b9d7c86baf21ed3c24e818f9225f59bded0 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -76,6 +76,7 @@ import org.chromium.content_public.common.Referrer;
 import org.chromium.net.NetError;
 import org.chromium.net.NetworkChangeNotifier;
 import org.chromium.ui.base.ActivityWindowAndroid;
+import org.chromium.ui.base.EventHandler;
 import org.chromium.ui.base.PageTransition;
 import org.chromium.ui.base.ViewAndroidDelegate;
 import org.chromium.ui.base.WindowAndroid;
@@ -362,6 +363,8 @@ public class AwContents implements SmartClipProvider, PostMessageSender.PostMess
 
     private static String sCurrentLocales = "";
 
+    private EventHandler mEventHandler;
+
     private static final class AwContentsDestroyRunnable implements Runnable {
         private final long mNativeAwContents;
         // Hold onto a reference to the window (via its wrapper), so that it is not destroyed
@@ -3219,7 +3222,7 @@ public class AwContents implements SmartClipProvider, PostMessageSender.PostMess
             // to enter fixedLayoutSize mode is sent before the first resize
             // update.
             mLayoutSizer.onSizeChanged(w, h, ow, oh);
-            mContentViewCore.onPhysicalBackingSizeChanged(w, h);
+            getEventHandler().onPhysicalBackingSizeChanged(w, h);
             mContentViewCore.onSizeChanged(w, h, ow, oh);
             nativeOnSizeChanged(mNativeAwContents, w, h, ow, oh);
         }
@@ -3295,6 +3298,13 @@ public class AwContents implements SmartClipProvider, PostMessageSender.PostMess
         }
     }
 
+    private EventHandler getEventHandler() {
+        if (mEventHandler == null) {
+            mEventHandler = nativeGetEventHandler(mNativeAwContents);
+        }
+        return mEventHandler;
+    }
+
     // Return true if the GeolocationPermissionAPI should be used.
     @CalledByNative
     private boolean useLegacyGeolocationPermissionAPI() {
@@ -3398,4 +3408,5 @@ public class AwContents implements SmartClipProvider, PostMessageSender.PostMess
 
     private native void nativeGrantFileSchemeAccesstoChildProcess(long nativeAwContents);
     private native void nativeResumeLoadingCreatedPopupWebContents(long nativeAwContents);
+    private native EventHandler nativeGetEventHandler(long nativeAwContents);
 }