[Mac] Fix for fullscreen toolbar

chrome/browser/ui/cocoa/fullscreen_toolbar_controller.h

Index: chrome/browser/ui/cocoa/fullscreen_toolbar_controller.h
diff --git a/chrome/browser/ui/cocoa/fullscreen_toolbar_controller.h b/chrome/browser/ui/cocoa/fullscreen_toolbar_controller.h
index 8d54af9773d982149981497957028cea860c0aa7..a604461088002ef94f417a8c2b8475f62abf1b08 100644
--- a/chrome/browser/ui/cocoa/fullscreen_toolbar_controller.h
+++ b/chrome/browser/ui/cocoa/fullscreen_toolbar_controller.h
@@ -12,6 +12,7 @@
 #include "chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h"
 
 @class BrowserWindowController;
+@class CrTrackingArea;
 @class DropdownAnimation;
 
 namespace fullscreen_mac {
@@ -35,6 +36,25 @@ enum SlidingStyle {
 // when the animation finishes.  This is largely done for ease of
 // implementation; it is easier to check the mouse location at each animation
 // step than it is to manage a constantly-changing tracking area.
+//
+
+// The |toolbarFraction_| is usually set by |setMenuBarRevealProgress:|, which
+// is called by MenuBarRevealHandler(). This makes the toolbar show/hide in
+// sync with the menubar. However, there's an edge case that appears when the
+// sliding style is set to OMNIBOX_TABS_HIDDEN. If the user interacts with the
+// bottom half of the toolbar, the menubar will disappear and take the toolbar
+// with it. This prevents users from interacting properly with the omnibox and
+// bookmarks bar.
+//
+// To prevent the toolbar from disappearing when the user is still interacting
+// with it, we lock its visibility so that the toolbar will remain, even after
+// the menubar had disappeared. The tracking area is then used to check if the
+// user is still interacting with the toolbar. Once we receive a mouse exit
+// event, we release the visibility lock so that the toolbar can hidden by the
+// menubar (if it's still there) or via a DropdownAnimation (if the menubar is
+// gone).
+
+// TODO (spqchan): Write tests for this class. See crbug.com/640064.
 @interface FullscreenToolbarController : NSObject<NSAnimationDelegate> {
  @private
   // Our parent controller.
@@ -43,6 +63,18 @@ enum SlidingStyle {
   // Whether or not we are in fullscreen mode.
   BOOL inFullscreenMode_;
 
+  // The content view for the window.  This is nil when not in fullscreen mode.
+  NSView* contentView_;  // weak
+
+  // The frame for the tracking area. The value is the toolbar overlay's frame
+  // with additional height added at the bottom.
+  NSRect trackingAreaFrame_;
+
+  // The tracking area associated with the toolbar overlay bar. This tracking
+  // area is used to keep the toolbar active if the menubar had animated out
+  // but the mouse is still on the toolbar.
+  base::scoped_nsobject<CrTrackingArea> trackingArea_;
+
   // Pointer to the currently running animation.  Is nil if no animation is
   // running.
   base::scoped_nsobject<DropdownAnimation> currentAnimation_;
@@ -87,14 +119,15 @@ enum SlidingStyle {
 - (id)initWithBrowserController:(BrowserWindowController*)controller
                           style:(fullscreen_mac::SlidingStyle)style;
 
-// Informs the controller that the browser has entered or exited presentation
+// Informs the controller that the browser has entered or exited fullscreen
 // mode. |-setupFullscreenToolbarForContentView:showDropdown:| should be called
 // after the window is setup, just before it is shown. |-exitFullscreenMode|
 // should be called before any views are moved back to the non-fullscreen
 // window.  If |-setupFullscreenToolbarForContentView:showDropdown:| is called,
 // it must be balanced with a call to |-exitFullscreenMode| before the
 // controller is released.
-- (void)setupFullscreenToolbarWithDropdown:(BOOL)showDropdown;
+- (void)setupFullscreenToolbarForContentView:(NSView*)contentView
+                                showDropdown:(BOOL)showDropdown;
 - (void)exitFullscreenMode;
 
 // Returns the amount by which the floating bar should be offset downwards (to
@@ -124,10 +157,16 @@ enum SlidingStyle {
 // only be revealed if the mouse is there.
 - (BOOL)isMouseOnScreen;
 
-// Returns true if the browser is in the process of entering/exiting
+// Sets |trackingAreaFrame_| from the given overlay frame.
+- (void)setTrackingAreaFromOverlayFrame:(NSRect)frame;
+
+// Returns YES if the browser is in the process of entering/exiting
 // fullscreen.
 - (BOOL)isFullscreenTransitionInProgress;
 
+// Returns YES if the browser in in fullscreen.
+- (BOOL)isInFullscreen;
+
 @end
 
 // Private methods exposed for testing.
@@ -140,7 +179,8 @@ enum SlidingStyle {
 
 // Updates the local state that reflects the fraction of the toolbar area that
 // is showing. This function has the side effect of changing the AppKit
-// Fullscreen option for whether the menu bar is shown.
+// Fullscreen option for whether the menu bar is shown. If the toolbar
+// visibility is locked, the fraction will be updated to 1.0;
 - (void)changeToolbarFraction:(CGFloat)fraction;
 
 @end