Corrently exclude FontCustomPlatformDataWin for non-GDI

Change blink_platform.gyp to correctly exclude
FontCustomPlatformDataWin.cpp.

R=dglazkov@chromium.org
BUG=

Review URL: https://codereview.chromium.org/109833003

git-svn-id: svn://svn.chromium.org/blink/trunk@163990 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix the PlatformAppBrowserTest.MutationEventsDisabled browser_test when getting WebPermissionClient from the WebFrame.

My chrome-side change https://codereview.chromium.org/104833006/ exposed this bug.

BUG=304341
R=japhet@chromium.org

Review URL: https://codereview.chromium.org/113453008

git-svn-id: svn://svn.chromium.org/blink/trunk@163991 bbb929c8-8fbe-4397-9dbb-9b2b20218538