Implement new compositor and ContentViewCore reparenting for VR Shell.

content/browser/android/content_view_core_impl.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/android/content_view_core_impl.h"
 
 #include <stddef.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
@@ skipping 258 matching lines @@
   if (!j_obj.is_null()) {
     Java_ContentViewCore_onNativeContentViewCoreDestroyed(
         env, j_obj, reinterpret_cast<intptr_t>(this));
   }
 }
 
 void ContentViewCoreImpl::UpdateWindowAndroid(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj,
     jlong window_android) {
+  if (!window_android || view_.GetWindowAndroid()) {
+    FOR_EACH_OBSERVER(ContentViewCoreImplObserver, observer_list_,

[Ted C, 2016/09/20 19:57:07]

per my other comment, let's try to avoid this by setting it to null as part of
the VR path.

[mthiesse, 2016/09/20 20:56:08]

Done.

+                      OnDetachedFromWindow());
+    view_.RemoveFromParent();
+  }
   if (window_android) {
-    DCHECK(!view_.GetWindowAndroid());
     ui::WindowAndroid* window =
         reinterpret_cast<ui::WindowAndroid*>(window_android);
     window->AddChild(&view_);
-    FOR_EACH_OBSERVER(ContentViewCoreImplObserver,
-                      observer_list_,
+    FOR_EACH_OBSERVER(ContentViewCoreImplObserver, observer_list_,
                       OnAttachedToWindow());
-  } else {
-    FOR_EACH_OBSERVER(ContentViewCoreImplObserver,
-                      observer_list_,
-                      OnDetachedFromWindow());
-    view_.RemoveFromParent();
   }
 }
 
 base::android::ScopedJavaLocalRef<jobject>
 ContentViewCoreImpl::GetWebContentsAndroid(JNIEnv* env,
                                            const JavaParamRef<jobject>& obj) {
   return web_contents_->GetJavaWebContents();
 }
 
 base::android::ScopedJavaLocalRef<jobject>
@@ skipping 1301 matching lines @@
     return ScopedJavaLocalRef<jobject>();
 
   return view->GetJavaObject();
 }
 
 bool RegisterContentViewCore(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content