Revert of [Athena, Cleanup] rename WidnowManager::GetInstance -> ::Get (patchset #1 id:40001 of https://codereview.chromium.org/599683003/)

Reason for revert:
Seems to cause crash in two tests; the crash is in athena_test_base. Likely it isn't possible to call AthenaEnv::Get()->OnTerminating(); in all cases.

Example: https://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%283%29/builds/36880/steps/athena_unittests/logs/TerminatingCallback

Original issue's description:
> rename WidnowManager::GetInstance -> ::Get
> call OnTerminating in unit test.
>
> BUG=None
>
> Committed: https://crrev.com/828338e278350941febbfbede2b34d721be6dab1
> Cr-Commit-Position: refs/heads/master@{#296348}

TBR=mukai@chromium.org,skuhne@chromium.org,oshima@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=None

Review URL: https://codereview.chromium.org/601753002

Cr-Commit-Position: refs/heads/master@{#296392}

2 files changed, 24 insertions, 23 deletions

diff --git a/athena/home/home_card_impl.cc b/athena/home/home_card_impl.cc
index 3b285fb..2b11db4 100644
--- a/athena/home/home_card_impl.cc
+++ b/athena/home/home_card_impl.cc
@@ -197,7 +197,7 @@ class HomeCardView : public views::WidgetDelegateView {
   virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE {
     if (HomeCard::Get()->GetState() == HomeCard::VISIBLE_MINIMIZED &&
         event.IsLeftMouseButton() && event.GetClickCount() == 1) {
-      athena::WindowManager::Get()->ToggleOverview();
+      athena::WindowManager::GetInstance()->ToggleOverview();
       return true;
     }
     return false;
@@ -232,12 +232,12 @@ HomeCardImpl::HomeCardImpl(AppModelBuilder* model_builder)
       activation_client_(NULL) {
   DCHECK(!instance);
   instance = this;
-  WindowManager::Get()->AddObserver(this);
+  WindowManager::GetInstance()->AddObserver(this);
 }
 
 HomeCardImpl::~HomeCardImpl() {
   DCHECK(instance);
-  WindowManager::Get()->RemoveObserver(this);
+  WindowManager::GetInstance()->RemoveObserver(this);
   if (activation_client_)
     activation_client_->RemoveObserver(this);
   home_card_widget_->CloseNow();
@@ -379,7 +379,7 @@ void HomeCardImpl::OnGestureEnded(State final_state, bool is_fling) {
   if (state_ != final_state &&
       (state_ == VISIBLE_MINIMIZED || final_state == VISIBLE_MINIMIZED)) {
     SetState(final_state);
-    WindowManager::Get()->ToggleOverview();
+    WindowManager::GetInstance()->ToggleOverview();
   } else {
     state_ = final_state;
     // When the animation happens after a fling, EASE_IN_OUT would cause weird
diff --git a/athena/home/home_card_unittest.cc b/athena/home/home_card_unittest.cc
index ce28ba5..fe7083f 100644
--- a/athena/home/home_card_unittest.cc
+++ b/athena/home/home_card_unittest.cc
@@ -48,13 +48,13 @@ TEST_F(HomeCardTest, BasicTransition) {
   EXPECT_EQ(work_area_height, home_card->GetTargetBounds().y());
   EXPECT_EQ(wm::ShadowType::SHADOW_TYPE_NONE, wm::GetShadowType(home_card));
 
-  WindowManager::Get()->ToggleOverview();
+  WindowManager::GetInstance()->ToggleOverview();
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
   EXPECT_EQ(screen_height - kHomeCardHeight, home_card->GetTargetBounds().y());
   EXPECT_EQ(wm::ShadowType::SHADOW_TYPE_RECTANGULAR,
             wm::GetShadowType(home_card));
 
-  WindowManager::Get()->ToggleOverview();
+  WindowManager::GetInstance()->ToggleOverview();
   EXPECT_EQ(HomeCard::VISIBLE_MINIMIZED, HomeCard::Get()->GetState());
   EXPECT_EQ(work_area_height, home_card->GetTargetBounds().y());
   EXPECT_EQ(wm::ShadowType::SHADOW_TYPE_NONE, wm::GetShadowType(home_card));
@@ -70,7 +70,7 @@ TEST_F(HomeCardTest, VirtualKeyboardTransition) {
   EXPECT_EQ(HomeCard::VISIBLE_MINIMIZED, HomeCard::Get()->GetState());
 
   // bottom -> centered for virtual keyboard.
-  WindowManager::Get()->ToggleOverview();
+  WindowManager::GetInstance()->ToggleOverview();
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
   HomeCard::Get()->UpdateVirtualKeyboardBounds(vk_bounds);
   EXPECT_EQ(HomeCard::VISIBLE_CENTERED, HomeCard::Get()->GetState());
@@ -93,7 +93,7 @@ TEST_F(HomeCardTest, ToggleOverviewWithVirtualKeyboard) {
 
   // Toogle overview revives the bottom home card. Home card also gets
   /// activated which will close the virtual keyboard.
-  WindowManager::Get()->ToggleOverview();
+  WindowManager::GetInstance()->ToggleOverview();
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
   aura::Window* home_card = GetHomeCardWindow();
   EXPECT_TRUE(wm::IsActiveWindow(home_card));
@@ -103,7 +103,7 @@ TEST_F(HomeCardTest, ToggleOverviewWithVirtualKeyboard) {
 TEST_F(HomeCardTest, AppSelection) {
   EXPECT_EQ(HomeCard::VISIBLE_MINIMIZED, HomeCard::Get()->GetState());
 
-  WindowManager::Get()->ToggleOverview();
+  WindowManager::GetInstance()->ToggleOverview();
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
 
   athena::ActivityFactory::Get()->CreateWebActivity(
@@ -122,7 +122,7 @@ TEST_F(HomeCardTest, Accelerators) {
   EXPECT_EQ(HomeCard::VISIBLE_MINIMIZED, HomeCard::Get()->GetState());
 
   // Do nothing for BOTTOM.
-  WindowManager::Get()->ToggleOverview();
+  WindowManager::GetInstance()->ToggleOverview();
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
   generator.PressKey(ui::VKEY_L, ui::EF_CONTROL_DOWN);
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
@@ -146,12 +146,12 @@ TEST_F(HomeCardTest, MouseClick) {
   generator.ClickLeftButton();
 
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   // Further clicks are simply ignored.
   generator.ClickLeftButton();
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 }
 
 TEST_F(HomeCardTest, Gestures) {
@@ -167,7 +167,7 @@ TEST_F(HomeCardTest, Gestures) {
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   // Too short moves. Nothing has changed.
   generator.GestureScrollSequence(gfx::Point(x, bottom - 40),
@@ -175,14 +175,14 @@ TEST_F(HomeCardTest, Gestures) {
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   generator.GestureScrollSequence(gfx::Point(x, bottom - 40),
                                   gfx::Point(x, bottom - 20),
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   // Swipe up to the centered state.
   generator.GestureScrollSequence(gfx::Point(x, bottom - 40),
@@ -190,7 +190,7 @@ TEST_F(HomeCardTest, Gestures) {
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_CENTERED, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   // Swipe up from centered; nothing has to be changed.
   generator.GestureScrollSequence(gfx::Point(x, bottom - 300),
@@ -198,7 +198,7 @@ TEST_F(HomeCardTest, Gestures) {
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_CENTERED, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   // Swipe down slightly; nothing has to be changed.
   generator.GestureScrollSequence(gfx::Point(x, bottom - 300),
@@ -206,7 +206,7 @@ TEST_F(HomeCardTest, Gestures) {
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_CENTERED, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   // Swipe down to the bottom state.
   generator.GestureScrollSequence(gfx::Point(x, 10),
@@ -214,14 +214,14 @@ TEST_F(HomeCardTest, Gestures) {
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_BOTTOM, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   generator.GestureScrollSequence(gfx::Point(x, bottom - 40),
                                   gfx::Point(x, bottom - 300),
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_CENTERED, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 
   // Swipe down to the minimized state.
   generator.GestureScrollSequence(gfx::Point(x, 10),
@@ -229,7 +229,8 @@ TEST_F(HomeCardTest, Gestures) {
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_MINIMIZED, HomeCard::Get()->GetState());
-  EXPECT_FALSE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_FALSE(WindowManager::GetInstance()->IsOverviewModeActive());
+
 }
 
 TEST_F(HomeCardTest, GesturesToFullDirectly) {
@@ -245,7 +246,7 @@ TEST_F(HomeCardTest, GesturesToFullDirectly) {
                                   base::TimeDelta::FromSeconds(1),
                                   10);
   EXPECT_EQ(HomeCard::VISIBLE_CENTERED, HomeCard::Get()->GetState());
-  EXPECT_TRUE(WindowManager::Get()->IsOverviewModeActive());
+  EXPECT_TRUE(WindowManager::GetInstance()->IsOverviewModeActive());
 }
 
 TEST_F(HomeCardTest, KeyboardFocus) {
@@ -253,7 +254,7 @@ TEST_F(HomeCardTest, KeyboardFocus) {
   aura::Window* home_card = GetHomeCardWindow();
   ASSERT_FALSE(IsSearchBoxFocused(home_card));
 
-  WindowManager::Get()->ToggleOverview();
+  WindowManager::GetInstance()->ToggleOverview();
   ASSERT_FALSE(IsSearchBoxFocused(home_card));
 
   ui::test::EventGenerator generator(root_window());