(sorry for the long time to give details, did not received notif on topic update).
I simplified/narrowed a bit the problem:
As in my full project I use a more complex html dom I tested using Html5HelloWOrld, just added a full screen button.
So the html is the one from the sample untouched.
Here is the policy.
var policy = new cc.ResolutionPolicy(cc.ContainerStrategy.PROPORTION_TO_FRAME,cc.ContentStrategy.SHOW_ALL);
cc.EGLView.getInstance().resizeWithBrowserSize(true); //required for Chrome
Note: resizeWithBrowserSize is needed in Chrome to have the content of canvas “zoomed” full screen. In firefox removing it has no effect, is that normal.
Anyway in Chrome, everything looks fine. Black bars appear on the top and bottom as requested by the policy. Now on Firefox the canvas is streched to fill vertically the screen.
Attached are the results when going full screen with Chrome and FireFox.
Hope it helps.