Created attachment 104242 [details]
1. Load the attached testcase in a window with a 1.0 backing scale factor
2. Open a window with a 2.0 backing scale factor
3. Move the WebView from the first window to the second
The testcase will still say the device pixel ratio is 1, but should say it is 2.
Created attachment 104350 [details]
Update the device scale factor when the WebView's window changes
Committed r93315: <http://trac.webkit.org/changeset/93315>