ash: Move ShelfWidget ownership to WmShelf and refactor access to it

ash/wm/overview/window_selector_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 #include <vector>
 
 #include "ash/aura/wm_window_aura.h"
 #include "ash/common/accessibility_delegate.h"
 #include "ash/common/accessibility_types.h"
@@ skipping 615 matching lines @@
   EXPECT_EQ(wm::WINDOW_STATE_TYPE_DOCKED,
             wm::GetWindowState(docked1.get())->GetStateType());
   EXPECT_EQ(wm::WINDOW_STATE_TYPE_DOCKED_MINIMIZED,
             wm::GetWindowState(docked2.get())->GetStateType());
 
   ToggleOverview();
 
   EXPECT_FALSE(WindowsOverlapping(window1.get(), window2.get()));
 
   gfx::Rect container_bounds = docked1->parent()->bounds();
-  ShelfWidget* shelf = Shell::GetPrimaryRootWindowController()->shelf_widget();
+  ShelfWidget* shelf = GetPrimaryShelf()->shelf_widget();
   DockedWindowLayoutManager* manager =
       DockedWindowLayoutManager::Get(WmWindowAura::Get(docked1.get()));
 
   if (ash::MaterialDesignController::IsOverviewMaterial()) {
     // Docked windows get shown and transformed.
     EXPECT_TRUE(docked2->IsVisible());
 
     // Docked area shrinks.
     DockedWindowLayoutManager* manager =
         DockedWindowLayoutManager::Get(WmWindowAura::Get(docked1.get()));
@@ skipping 520 matching lines @@
   EXPECT_TRUE(wm::GetWindowState(window1.get())->IsFullscreen());
 }
 
 // Tests that the shelf dimming state is removed while in overview and restored
 // on exiting overview.
 TEST_P(WindowSelectorTest, OverviewUndimsShelf) {
   gfx::Rect bounds(0, 0, 400, 400);
   std::unique_ptr<aura::Window> window1(CreateWindow(bounds));
   wm::WindowState* window_state = wm::GetWindowState(window1.get());
   window_state->Maximize();
-  ShelfWidget* shelf = Shell::GetPrimaryRootWindowController()->shelf_widget();
+  ShelfWidget* shelf = GetPrimaryShelf()->shelf_widget();
   EXPECT_TRUE(shelf->GetDimsShelf());
   ToggleOverview();
   EXPECT_FALSE(shelf->GetDimsShelf());
   ToggleOverview();
   EXPECT_TRUE(shelf->GetDimsShelf());
 }
 
 // Tests that entering overview when a fullscreen window is active in maximized
 // mode correctly applies the transformations to the window and correctly
 // updates the window bounds on exiting overview mode: http://crbug.com/401664.
@@ skipping 931 matching lines @@
       bounds.y());
   EXPECT_LE(transformed_rect.bottom(), bounds.bottom());
   EXPECT_NEAR(transformed_rect.x() - bounds.x(),
               bounds.right() - transformed_rect.right(), 1);
   EXPECT_NEAR(
       transformed_rect.y() + (int)(scale * inset) - header_height - bounds.y(),
       bounds.bottom() - transformed_rect.bottom(), 1);
 }
 
 }  // namespace ash