Added HALF, FULLSCREEN_ALL_APPS, and FULLSCREEN_SEARCH.

ash/app_list/app_list_presenter_delegate.h

Index: ash/app_list/app_list_presenter_delegate.h
diff --git a/ash/app_list/app_list_presenter_delegate.h b/ash/app_list/app_list_presenter_delegate.h
index e7cfcf4b6736b0c9b00cf9e82e2c8e980532cd3f..d6a7f7ff9c52be8a09b528fd249ec26b8be52f72 100644
--- a/ash/app_list/app_list_presenter_delegate.h
+++ b/ash/app_list/app_list_presenter_delegate.h
@@ -8,6 +8,7 @@
 #include <stdint.h>
 
 #include "ash/ash_export.h"
+#include "ash/shelf/shelf_observer.h"
 #include "ash/shell_observer.h"
 #include "base/macros.h"
 #include "ui/app_list/presenter/app_list_presenter_delegate.h"
@@ -35,7 +36,8 @@ class ASH_EXPORT AppListPresenterDelegate
     : public app_list::AppListPresenterDelegate,
       public ui::EventHandler,
       public keyboard::KeyboardControllerObserver,
-      public ShellObserver {
+      public ShellObserver,
+      public ShelfObserver {

[xiyuan, 2017/06/13 21:38:58]

Is ShelfObserver used?

[newcomer, 2017/06/13 22:22:47]

no, thanks!

  public:
   AppListPresenterDelegate(
       app_list::AppListPresenterImpl* presenter,
@@ -52,6 +54,10 @@ class ASH_EXPORT AppListPresenterDelegate
   void UpdateBounds() override;
   gfx::Vector2d GetVisibilityAnimationOffset(
       aura::Window* root_window) override;
+  // Whether the maximize mode controller is active.
+  bool IsMaximizeModeActive() const;

[xiyuan, 2017/06/13 21:38:58]

This and IsSideShelf() can go into cc file in anonymous namespace.

[newcomer, 2017/06/13 22:22:47]

Done.

+  // Whether the shelf is oriented on the side, not on the bottom.
+  bool IsSideShelf() const;
 
  private:
   void ProcessLocatedEvent(ui::LocatedEvent* event);
@@ -64,8 +70,13 @@ class ASH_EXPORT AppListPresenterDelegate
   void OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) override;
   void OnKeyboardClosed() override;
 
+  // ShelfObserver overrides:
+  void OnShelfIconPositionChanged();

[oshima, 2017/06/13 22:26:04]

override?

[newcomer, 2017/06/13 23:00:39]

Function removed as a side effect of xiyuan@'s comment. But correct, thanks!

+
   // ShellObserver overrides:
   void OnOverviewModeStarting() override;
+  void OnMaximizeModeStarted() override;
+  void OnMaximizeModeEnded() override;
 
   // Whether the app list is visible (or in the process of being shown).
   bool is_visible_ = false;