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..56f1126eb7e1cbfb1b98ce14f24ecc9c23311bf7 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"
@@ -274,19 +275,20 @@ ContentViewCoreImpl::~ContentViewCoreImpl() {
 void ContentViewCoreImpl::UpdateWindowAndroid(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj,
+    const base::android::JavaParamRef<jobject>& jview_root,
     jlong window_android) {
-  ui::ViewAndroid* view = GetViewAndroid();
   ui::WindowAndroid* window =

[boliu, 2017/01/04 18:58:06]

should DCHECK that window and view root are either both null or both not null

actually.. perhaps should pass in view_root only since can get the window
android from the view root? Probably should rename the method :)

[Jinsuk Kim, 2017/01/05 11:03:12]

Renamed to UpdateViewRoot.

       reinterpret_cast<ui::WindowAndroid*>(window_android);
   if (window == GetWindowAndroid())

[boliu, 2017/01/04 18:58:05]

this is not enough, what if view_root is different?

[Jinsuk Kim, 2017/01/05 11:03:12]

Used view_root instead. ViewRoot and WA always come in pair now, so this will do
the job.

     return;
+  ui::ViewAndroid* view = GetViewAndroid();
+  view->RemoveFromParent();

[boliu, 2017/01/04 18:58:06]

Remove/AddChild should stay where they used to be

[Jinsuk Kim, 2017/01/05 11:03:12]

Done.

+  ui::ViewRoot::FromJavaObject(env, jview_root)->AddChild(view);

[boliu, 2017/01/04 18:58:05]

probably should match WindowAndroid pattern here too, ie have a getNativePointer
method on the java class

[Jinsuk Kim, 2017/01/05 11:03:12]

Done.

   if (GetWindowAndroid()) {
     for (auto& observer : observer_list_)
       observer.OnDetachedFromWindow();
-    view->RemoveFromParent();
   }
   if (window) {
-    window->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,
+           const JavaParamRef<jobject>& jview_root,
            jfloat dipScale,
            const JavaParamRef<jobject>& retained_objects_set) {
   WebContentsImpl* web_contents = static_cast<WebContentsImpl*>(
@@ -1542,11 +1544,7 @@ 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::FromJavaObject(env, jview_root)->AddChild(view_android);
 
   // TODO: pass dipScale.
   ContentViewCoreImpl* view = new ContentViewCoreImpl(