Lock rotation when screen is manually rotated.

ash/wm/maximize_mode/maximize_mode_controller.h

Index: ash/wm/maximize_mode/maximize_mode_controller.h
diff --git a/ash/wm/maximize_mode/maximize_mode_controller.h b/ash/wm/maximize_mode/maximize_mode_controller.h
index 4d19dcc8e80d4d149ced7b9aef9ef21d7bc375bd..fd2efe5acb13e105eb3e53964619082c9c17cac3 100644
--- a/ash/wm/maximize_mode/maximize_mode_controller.h
+++ b/ash/wm/maximize_mode/maximize_mode_controller.h
@@ -10,6 +10,7 @@
 #include "ash/display/display_manager.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
+#include "ui/gfx/display.h"
 
 namespace ui {
 class EventHandler;
@@ -69,6 +70,14 @@ class ASH_EXPORT MaximizeModeController : public AccelerometerObserver {
   void SetDisplayRotation(DisplayManager* display_manager,
                           gfx::Display::Rotation rotation);
 
+  // Enables MaximizeModeWindowManager, and determines the current state of
+  // rotation lock.
+  void EnterMaximizeMode();
+
+  // Removes MaximizeModeWindowManager and resets the display rotation if there
+  // is no rotation lock.
+  void LeaveMaximizeMode();
+
   // An event targeter controller which traps mouse and keyboard events while
   // maximize mode is engaged.
   scoped_ptr<MaximizeModeEventBlocker> event_blocker_;
@@ -85,6 +94,10 @@ class ASH_EXPORT MaximizeModeController : public AccelerometerObserver {
   // True when the screen's orientation is being changed.
   bool in_set_screen_rotation_;
 
+  // The rotation of the display set by the user. This rotation will be
+  // restored upon exiting maximize mode.
+  gfx::Display::Rotation user_rotation_;
+
   DISALLOW_COPY_AND_ASSIGN(MaximizeModeController);
 };