cros/ash: Cancel screenshot mode if screenshot is cancelled or not taken.

ash/utility/screenshot_controller.h

Index: ash/utility/screenshot_controller.h
diff --git a/ash/utility/screenshot_controller.h b/ash/utility/screenshot_controller.h
index 8416bbd3d2731dcf0334d87e81caa4bc358a2a52..65a6466654bd5b0fa23dfc88daf9ffe986d07780 100644
--- a/ash/utility/screenshot_controller.h
+++ b/ash/utility/screenshot_controller.h
@@ -12,6 +12,7 @@
 
 #include "ash/ash_export.h"
 #include "ash/common/shell_observer.h"
+#include "base/callback.h"
 #include "base/macros.h"
 #include "ui/aura/window_observer.h"
 #include "ui/display/display_observer.h"
@@ -57,6 +58,13 @@ class ASH_EXPORT ScreenshotController : public ui::EventHandler,
   // Cancels any active screenshot session.
   void CancelScreenshotSession();
 
+  // Set a function that will be called when the current screenshot session has
+  // been completed or cancelled. This is reset after the screenshot session is
+  // done.
+  void set_on_screenshot_session_done(const base::Closure& on_done) {
+    on_screenshot_session_done_ = on_done;
+  }
+
   // If set to true, then only events generated by a pen can be used to select
   // the area to take a screenshot of. This is reset to false after a screenshot
   // operation is completed.
@@ -108,6 +116,8 @@ class ASH_EXPORT ScreenshotController : public ui::EventHandler,
   // screenshot region.
   bool pen_events_only_ = false;
 
+  base::Closure on_screenshot_session_done_;
+
   // The data to build the screenshot region.
   gfx::Point start_position_;
   aura::Window* root_window_;