Introduce ViewRoot forwarding input/view events to native

chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanelContent.java

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanelContent.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanelContent.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanelContent.java
index f13b2897fcf7d36a2d6d0c40830118212f33780d..25d4530367c05259ece5d661b6f5993a5e21abfa 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanelContent.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanelContent.java
@@ -27,6 +27,7 @@ import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.content_public.browser.WebContentsObserver;
 import org.chromium.ui.base.ViewAndroidDelegate;
+import org.chromium.ui.base.ViewRoot;
 
 /**
  * Content container for an OverlayPanel. This class is responsible for the management of the
@@ -38,6 +39,9 @@ public class OverlayPanelContent {
     /** The ContentViewCore that this panel will display. */
     private ContentViewCore mContentViewCore;
 
+    /** The ViewRoot used to forward view/input events to native. */
+    private ViewRoot mViewRoot;
+
     /** The pointer to the native version of this class. */
     private long mNativeOverlayPanelContentPtr;
 
@@ -241,17 +245,19 @@ public class OverlayPanelContent {
         mContentViewCore = createContentViewCore(mActivity);
 
         ContentView cv = ContentView.createContentView(mActivity, mContentViewCore);
+        mViewRoot = ViewRoot.create(mActivity.getWindowAndroid());
         if (mContentViewWidth != 0 || mContentViewHeight != 0) {
             int width = mContentViewWidth == 0 ? ContentView.DEFAULT_MEASURE_SPEC
                     : MeasureSpec.makeMeasureSpec(mContentViewWidth, MeasureSpec.EXACTLY);
             int height = mContentViewHeight == 0 ? ContentView.DEFAULT_MEASURE_SPEC
                     : MeasureSpec.makeMeasureSpec(mContentViewHeight, MeasureSpec.EXACTLY);
             cv.setDesiredMeasureSpec(width, height);
-            mActivity.getCompositorViewHolder().setOverlayContentInfo(cv, width, height);
+            mActivity.getCompositorViewHolder().setOverlayContentInfo(cv, mViewRoot, width, height);
         }
 
         // Creates an initially hidden WebContents which gets shown when the panel is opened.
         WebContents panelWebContents = WebContentsFactory.createWebContents(false, true);
+        panelWebContents.initViewRoot(mViewRoot);
 
         // Dummny ViewAndroidDelegate since the container view for overlay panel is
         // never added to the view hierarchy.
@@ -460,6 +466,14 @@ public class OverlayPanelContent {
     }
 
     /**
+     * @return {@link ViewRoot} instance used to forward view/input events.
+     */
+    // package-visible
+    ViewRoot getViewRoot() {
+        return mViewRoot;
+    }
+
+    /**
      * @return This panel's ContentViewCore.
      */
     @VisibleForTesting