[ash] Make chrome's immersive mode watch properties.

Instead of implementing an ash specific observer type, watch shared
properties on the aura::Window instead. This removes dependence on
non-public ash types, and simplifies all three ashs (classic,mus,mash)
so they go through the same code path.

Bug: 640381
Change-Id: I1837202ae3fadd177c2a54b31d6cc31ed974b621
Test: ImmersiveModeControllerAshTest.*, Manual in all 3 configurations
Reviewed-on: https://chromium-review.googlesource.com/685538Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Elliot Glaysher <erg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504716}

chrome/browser/ui/views/frame/immersive_mode_controller_ash.cc

@@ -5,6 +5,7 @@
 #include "chrome/browser/ui/views/frame/immersive_mode_controller_ash.h"
 
 #include "ash/public/cpp/immersive/immersive_revealed_lock.h"
+#include "ash/public/cpp/window_properties.h"
 #include "ash/shell.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
 #include "ash/wm/window_state.h"
@@ -204,30 +205,18 @@ void ImmersiveModeControllerAsh::EnableWindowObservers(bool enable) {
     return;
   observers_enabled_ = enable;
 
+  aura::Window* target_window = ash_util::IsRunningInMash()
+                                    ? native_window_->GetRootWindow()
+                                    : native_window_;
+
   content::Source<FullscreenController> source(browser_view_->browser()
                                                    ->exclusive_access_manager()
                                                    ->fullscreen_controller());
   if (enable) {
-    if (ash_util::IsRunningInMash()) {
-      browser_view_->GetWidget()->GetNativeView()->GetRootWindow()->AddObserver(
-          this);
-      // TODO: http://crbug.com/640381.
-      NOTIMPLEMENTED();
-    } else {
-      ash::wm::GetWindowState(native_window_)->AddObserver(this);
-    }
+    target_window->AddObserver(this);
     registrar_.Add(this, chrome::NOTIFICATION_FULLSCREEN_CHANGED, source);
   } else {
-    if (ash_util::IsRunningInMash()) {
-      browser_view_->GetWidget()
-          ->GetNativeView()
-          ->GetRootWindow()
-          ->RemoveObserver(this);
-      // TODO: http://crbug.com/640381.
-      NOTIMPLEMENTED();
-    } else {
-      ash::wm::GetWindowState(native_window_)->RemoveObserver(this);
-    }
+    target_window->RemoveObserver(this);
     registrar_.Remove(this, chrome::NOTIFICATION_FULLSCREEN_CHANGED, source);
   }
 }
@@ -341,20 +330,6 @@ ImmersiveModeControllerAsh::GetVisibleBoundsInScreen() const {
   return bounds_in_screen;
 }
 
-// TODO(erg): Can we just observer the key change here?
-void ImmersiveModeControllerAsh::OnPostWindowStateTypeChange(
-    ash::wm::WindowState* window_state,
-    ash::mojom::WindowStateType old_type) {
-  // Disable immersive fullscreen when the user exits fullscreen without going
-  // through FullscreenController::ToggleBrowserFullscreenMode(). This is the
-  // case if the user exits fullscreen via the restore button.
-  if (controller_->IsEnabled() && !window_state->IsFullscreen() &&
-      !window_state->IsMinimized() &&
-      old_type == ash::mojom::WindowStateType::FULLSCREEN) {
-    browser_view_->FullscreenStateChanged();
-  }
-}
-
 void ImmersiveModeControllerAsh::Observe(
     int type,
     const content::NotificationSource& source,
@@ -380,11 +355,19 @@ void ImmersiveModeControllerAsh::Observe(
 void ImmersiveModeControllerAsh::OnWindowPropertyChanged(aura::Window* window,
                                                          const void* key,
                                                          intptr_t old) {
-  // In mash the window manager may move us out of immersive mode by changing
-  // the show state. When this happens notify the controller.
-  DCHECK(ash_util::IsRunningInMash());
-  if (key == aura::client::kShowStateKey &&
-      !browser_view_->GetWidget()->IsFullscreen()) {
-    SetEnabled(false);
+  if (key == ash::kWindowStateTypeKey) {
+    ash::mojom::WindowStateType new_state =
+        window->GetProperty(ash::kWindowStateTypeKey);
+    ash::mojom::WindowStateType old_state = ash::mojom::WindowStateType(old);
+
+    // Disable immersive fullscreen when the user exits fullscreen without going
+    // through FullscreenController::ToggleBrowserFullscreenMode(). This is the
+    // case if the user exits fullscreen via the restore button.
+    if (controller_->IsEnabled() &&
+        new_state != ash::mojom::WindowStateType::FULLSCREEN &&
+        new_state != ash::mojom::WindowStateType::MINIMIZED &&
+        old_state == ash::mojom::WindowStateType::FULLSCREEN) {
+      browser_view_->FullscreenStateChanged();
+    }
   }
 }

chrome/browser/ui/views/frame/immersive_mode_controller_ash.h

@@ -9,7 +9,6 @@
 
 #include "ash/public/cpp/immersive/immersive_fullscreen_controller.h"
 #include "ash/public/cpp/immersive/immersive_fullscreen_controller_delegate.h"
-#include "ash/wm/window_state_observer.h"
 #include "base/macros.h"
 #include "chrome/browser/ui/views/frame/immersive_mode_controller.h"
 #include "content/public/browser/notification_observer.h"
@@ -26,7 +25,6 @@ class Window;
 class ImmersiveModeControllerAsh
     : public ImmersiveModeController,
       public ash::ImmersiveFullscreenControllerDelegate,
-      public ash::wm::WindowStateObserver,
       public content::NotificationObserver,
       public aura::WindowObserver {
  public:
@@ -73,11 +71,6 @@ class ImmersiveModeControllerAsh
   void SetVisibleFraction(double visible_fraction) override;
   std::vector<gfx::Rect> GetVisibleBoundsInScreen() const override;
 
-  // ash::wm::WindowStateObserver override:
-  void OnPostWindowStateTypeChange(
-      ash::wm::WindowState* window_state,
-      ash::mojom::WindowStateType old_type) override;
-
   // content::NotificationObserver override:
   void Observe(int type,
                const content::NotificationSource& source,