[Picture in Picture] Update play/pause icon size.

This change makes the icon.. less overwhelming. It will be smaller than
the minimum window size. Also, as many screen sizes are not very large
(e.g. 13-15'' laptops or 24'' monitors), and the non-scaled control
appears much more prominent than needed.

We've received some initial feedback that the icon appears very
in-your-face.

BUG: 836389
Change-Id: I593cecf2bfe167765319ee2c35920d7f224fafe6
Reviewed-on: https://chromium-review.googlesource.com/1043650
Commit-Queue: apacible <apacible@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556117}

chrome/browser/ui/views/overlay/overlay_window_views.cc

@@ -34,7 +34,7 @@ const int kResizeAreaCornerSize = 16;
 // TODO(apacible): Update sizes per UX feedback and when scaling is determined.
 // http://crbug.com/836389
 const gfx::Size kCloseIconSize = gfx::Size(50, 50);
-const gfx::Size kPlayPauseIconSize = gfx::Size(120, 120);
+const gfx::Size kPlayPauseIconSize = gfx::Size(90, 90);
 }  // namespace
 
 // OverlayWindow implementation of NonClientFrameView.