Introduce ViewRoot forwarding input/view events to native

content/browser/android/content_view_core_impl.cc

Index: content/browser/android/content_view_core_impl.cc
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index 0e7e53ecd062f22adeb47802398a9810a556d574..eae17efe66765697cbeb6618c7b2f6abfdbe3240 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -55,6 +55,7 @@
 #include "jni/DragEvent_jni.h"
 #include "third_party/WebKit/public/platform/WebInputEvent.h"
 #include "ui/android/view_android.h"
+#include "ui/android/view_root.h"
 #include "ui/android/window_android.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/ui_base_switches_util.h"
@@ -271,22 +272,23 @@ ContentViewCoreImpl::~ContentViewCoreImpl() {
   }
 }
 
-void ContentViewCoreImpl::UpdateWindowAndroid(
+void ContentViewCoreImpl::UpdateViewRoot(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj,
-    jlong window_android) {
+    jlong view_root_ptr) {
+  ui::ViewRoot* view_root = reinterpret_cast<ui::ViewRoot*>(view_root_ptr);
   ui::ViewAndroid* view = GetViewAndroid();
-  ui::WindowAndroid* window =
-      reinterpret_cast<ui::WindowAndroid*>(window_android);
-  if (window == GetWindowAndroid())
+  if (view_root == view->GetViewRoot())
     return;
-  if (GetWindowAndroid()) {
+
+  if (view->GetViewRoot()) {
     for (auto& observer : observer_list_)
       observer.OnDetachedFromWindow();
     view->RemoveFromParent();
   }
-  if (window) {
-    window->AddChild(view);
+
+  if (view_root) {
+    view_root->AddChild(view);
     for (auto& observer : observer_list_)
       observer.OnAttachedToWindow();
   }
@@ -1532,7 +1534,7 @@ jlong Init(JNIEnv* env,
            const JavaParamRef<jobject>& obj,
            const JavaParamRef<jobject>& jweb_contents,
            const JavaParamRef<jobject>& jview_android_delegate,
-           jlong jwindow_android,
+           jlong view_root_ptr,
            jfloat dipScale,
            const JavaParamRef<jobject>& retained_objects_set) {
   WebContentsImpl* web_contents = static_cast<WebContentsImpl*>(
@@ -1542,11 +1544,8 @@ jlong Init(JNIEnv* env,
   ui::ViewAndroid* view_android = web_contents->GetView()->GetNativeView();
   view_android->SetDelegate(jview_android_delegate);
   view_android->SetLayer(cc::Layer::Create());
-
-  ui::WindowAndroid* window_android =
-        reinterpret_cast<ui::WindowAndroid*>(jwindow_android);
-  DCHECK(window_android);
-  window_android->AddChild(view_android);
+  ui::ViewRoot* view_root = reinterpret_cast<ui::ViewRoot*>(view_root_ptr);
+  view_root->AddChild(view_android);
 
   // TODO: pass dipScale.
   ContentViewCoreImpl* view = new ContentViewCoreImpl(