Allow keyboard shortcuts can be captured by webpage when toolbar is not visible

chrome/browser/ui/browser_window.h

Index: chrome/browser/ui/browser_window.h
diff --git a/chrome/browser/ui/browser_window.h b/chrome/browser/ui/browser_window.h
index 25ded9161b5470971f8520c6f4d309c15f777d7d..add20d4ac5e8ce5c0ca9f6278d055370f3d58b53 100644
--- a/chrome/browser/ui/browser_window.h
+++ b/chrome/browser/ui/browser_window.h
@@ -220,9 +220,17 @@ class BrowserWindow : public ui::BaseWindow {
   // Returns whether the tab strip is editable (for extensions).
   virtual bool IsTabStripEditable() const = 0;
 
-  // Returns whether the tool bar is visible or not.
+  // Returns whether the toolbar is available or not. It's called "Visible()"
+  // to follow the name convention. But it does not indicate the visibility of
+  // the toolbar, i.e. toolbar may be hidden, and only visible when the mouse
+  // cursor is at a certain place.
+  // TODO(zijiehe): Rename Visible() functions into Available() to match their
+  // original meaning.
   virtual bool IsToolbarVisible() const = 0;
 
+  // Returns whether the toolbar is showing up on the screen.
+  virtual bool IsToolbarShowing() const = 0;
+
   // Shows the Update Recommended dialog box.
   virtual void ShowUpdateChromeDialog() = 0;