mac: Add basic layout unit test for fullscreen transition.

chrome/browser/ui/cocoa/presentation_mode_controller.mm

Index: chrome/browser/ui/cocoa/presentation_mode_controller.mm
diff --git a/chrome/browser/ui/cocoa/presentation_mode_controller.mm b/chrome/browser/ui/cocoa/presentation_mode_controller.mm
index d4e8c12c57df8dadaa9da00338238d984c832e09..be0781946fb33f018a6cbce107ce770b321bfb52 100644
--- a/chrome/browser/ui/cocoa/presentation_mode_controller.mm
+++ b/chrome/browser/ui/cocoa/presentation_mode_controller.mm
@@ -12,6 +12,7 @@
 #include "chrome/browser/fullscreen.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #import "chrome/browser/ui/cocoa/nsview_additions.h"
+#import "chrome/browser/ui/cocoa/presentation_mode_controller_private.h"
 #include "chrome/common/chrome_switches.h"
 #import "third_party/google_toolbox_for_mac/src/AppKit/GTMNSAnimation+Duration.h"
 
@@ -20,15 +21,6 @@ NSString* const kWillEnterFullscreenNotification =
 NSString* const kWillLeaveFullscreenNotification =
     @"WillLeaveFullscreenNotification";
 
-@interface PresentationModeController ()
-// Sets a new current floating bar shown fraction.  NOTE: This function has side
-// effects, such as modifying the system fullscreen mode (menu bar shown state).
-- (void)changeToolbarFraction:(CGFloat)fraction;
-
-// Callback for menu bar animations.
-- (void)setMenuBarRevealProgress:(CGFloat)progress;
-@end
-
 namespace {
 
 // The activation zone for the main menu is 4 pixels high; if we make it any