Add tab reparenting

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index ddb0f0ce1fb840d1ed944fc0e7a18a68f6385e85..80b42fc7cf29685e9bd21fa8c024f19df4f22475 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -1759,12 +1759,10 @@ void RenderWidgetHostViewAndroid::SetContentViewCore(
     selection_controller_.reset();
     ReleaseLocksOnSurface();
     resize = true;
-    if (content_view_core_) {
-      if (!content_view_core)
-        content_view_core_->RemoveObserver(this);
-      else
-        content_view_core->AddObserver(this);
-    }
+    if (content_view_core_ && !content_view_core)
+      content_view_core_->RemoveObserver(this);

[no sievers, 2016/02/25 19:23:16]

So that fixes the else-path where we might not have attached to the new CVC
previously if |content_view_core_| was null.

But also: why do we want to stay attached to |content_view_core_| if
|content_view_core| is not null?

[Yusuf, 2016/02/25 19:37:03]

Another good point. Right now, we never call a single widget with multiple CVCs
I believe. That is why I didn't add it. Added a condition for it as well just in
case.

+    else
+      content_view_core->AddObserver(this);
   }
 
   content_view_core_ = content_view_core;