Introduce ViewRoot forwarding 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 f868572acdf78ff9beea53b8581a82c4d16136e4..8ea63cda4db07f4ff829d6f7ad7f7a53792cae5f 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -1063,6 +1063,8 @@ public class AwContents implements SmartClipProvider, PostMessageSender.PostMess
                 mIoThreadClient, mInterceptNavigationDelegate);
         mWebContents = mContentViewCore.getWebContents();
         mNavigationController = mWebContents.getNavigationController();
+        mViewRoot = ViewRoot.create(mWindowAndroid.getWindowAndroid());
+        mWebContents.initViewRoot(mViewRoot);
         installWebContentsObserver();
         mSettings.setWebContents(webContents);
 
@@ -3209,7 +3211,7 @@ public class AwContents implements SmartClipProvider, PostMessageSender.PostMess
             // to enter fixedLayoutSize mode is sent before the first resize
             // update.
             mLayoutSizer.onSizeChanged(w, h, ow, oh);
-            getViewRoot().onPhysicalBackingSizeChanged(w, h);
+            mViewRoot.onPhysicalBackingSizeChanged(w, h);
             mContentViewCore.onSizeChanged(w, h, ow, oh);
             nativeOnSizeChanged(mNativeAwContents, w, h, ow, oh);
         }
@@ -3285,13 +3287,6 @@ public class AwContents implements SmartClipProvider, PostMessageSender.PostMess
         }
     }
 
-    private ViewRoot getViewRoot() {
-        if (mViewRoot == null) {
-            mViewRoot = nativeGetViewRoot(mNativeAwContents);
-        }
-        return mViewRoot;
-    }
-
     // Return true if the GeolocationPermissionAPI should be used.
     @CalledByNative
     private boolean useLegacyGeolocationPermissionAPI() {
@@ -3395,5 +3390,4 @@ public class AwContents implements SmartClipProvider, PostMessageSender.PostMess
 
     private native void nativeGrantFileSchemeAccesstoChildProcess(long nativeAwContents);
     private native void nativeResumeLoadingCreatedPopupWebContents(long nativeAwContents);
-    private native ViewRoot nativeGetViewRoot(long nativeAwContents);
 }