Introduce ViewRoot forwarding input/view events to native

content/browser/web_contents/web_contents_android.cc

Index: content/browser/web_contents/web_contents_android.cc
diff --git a/content/browser/web_contents/web_contents_android.cc b/content/browser/web_contents/web_contents_android.cc
index 422c0cb334bb6b63148c9121f26558a4c336d3eb..fff42517f17f3568c5df768c7026263d91e687b9 100644
--- a/content/browser/web_contents/web_contents_android.cc
+++ b/content/browser/web_contents/web_contents_android.cc
@@ -40,6 +40,7 @@
 #include "net/android/network_library.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/android/overscroll_refresh_handler.h"
+#include "ui/android/view_root.h"
 #include "ui/gfx/android/device_display_info.h"
 #include "ui/gfx/android/java_bitmap.h"
 #include "ui/gfx/geometry/rect.h"
@@ -665,6 +666,14 @@ void WebContentsAndroid::ReloadLoFiImages(JNIEnv* env,
   static_cast<WebContentsImpl*>(web_contents_)->ReloadLoFiImages();
 }
 
+void WebContentsAndroid::InitViewRoot(
+  JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& jobj,
+    const base::android::JavaParamRef<jobject>& jview_root) {
+  ui::ViewRoot* view_root = ui::ViewRoot::FromJavaObject(env, jview_root);
+  view_root->AddChild(web_contents_->GetView()->GetNativeView());
+}
+
 int WebContentsAndroid::DownloadImage(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj,