cros: Remove some OS platform ifdefs from ash

Ash only builds on Chrome OS, so there's no need for OS_CHROMEOS and OS_WIN
checks.

BUG=666773
TEST=compiles

Review-Url: https://codereview.chromium.org/2618143002
Cr-Commit-Position: refs/heads/master@{#442318}
diff --git a/ash/root_window_controller_unittest.cc b/ash/root_window_controller_unittest.cc
index 8da0816..48aadbd 100644
--- a/ash/root_window_controller_unittest.cc
+++ b/ash/root_window_controller_unittest.cc
@@ -1236,16 +1236,9 @@
   menu.reset();
 }
 
-// Resolution in UpdateDisplay is not being respected on Windows 8.
-#if defined(OS_WIN)
-#define MAYBE_DisplayRotation DISABLED_DisplayRotation
-#else
-#define MAYBE_DisplayRotation DisplayRotation
-#endif
-
 // Tests that the virtual keyboard correctly resizes with a change to display
 // orientation. See crbug/417612.
-TEST_F(VirtualKeyboardRootWindowControllerTest, MAYBE_DisplayRotation) {
+TEST_F(VirtualKeyboardRootWindowControllerTest, DisplayRotation) {
   UpdateDisplay("800x600");
   aura::Window* root_window = Shell::GetPrimaryRootWindow();
   aura::Window* keyboard_container =