Introduce ViewRoot to forward input/view events to native

blimp/client/core/contents/blimp_contents_view_impl_android.cc

Index: blimp/client/core/contents/blimp_contents_view_impl_android.cc
diff --git a/blimp/client/core/contents/blimp_contents_view_impl_android.cc b/blimp/client/core/contents/blimp_contents_view_impl_android.cc
index ee92657535fbdba39d2e31b5aaf073fac1ae2bc4..6205fbd40ef86adac9f56d0746360e935977a3cd 100644
--- a/blimp/client/core/contents/blimp_contents_view_impl_android.cc
+++ b/blimp/client/core/contents/blimp_contents_view_impl_android.cc
@@ -29,8 +29,8 @@ BlimpContentsViewImplAndroid::BlimpContentsViewImplAndroid(
       ime_dialog_(new ImeHelperDialog(blimp_contents->GetNativeWindow())) {
   blimp_view_ =
       base::MakeUnique<BlimpView>(blimp_contents->GetNativeWindow(), this);
-  view_ = base::MakeUnique<ui::ViewAndroid>(
-      blimp_view_->CreateViewAndroidDelegate());
+  view_ = base::MakeUnique<ui::ViewAndroid>();
+  view_->SetDelegate(blimp_view_->CreateViewAndroidDelegate());
   view_->SetLayer(contents_layer);
   blimp_contents->GetNativeWindow()->AddChild(view_.get());
 }