collect windows from mru_list in workspace_controller.

BUG=b:38505617
TEST=
  ash_unittests on ShelfLayoutManagerTest.AutohideShelfForAutohideWhenActiveWindow
  ash unittests on AppListPresenterDelegateTest.ShelfBackgroundRespondsToAppListBeingShown

Review-Url: https://codereview.chromium.org/2967543003
Cr-Commit-Position: refs/heads/master@{#486462}

ash/app_list/app_list_presenter_delegate.cc

@@ -15,6 +15,7 @@
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "ash/wm/maximize_mode/maximize_mode_controller.h"
+#include "ash/wm/window_state.h"
 #include "base/command_line.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_features.h"
@@ -120,6 +121,8 @@ void AppListPresenterDelegate::Init(app_list::AppListView* view,
     view->MaybeSetAnchorPoint(GetCenterOfDisplayForWindow(
         root_window, GetMinimumBoundsHeightForAppList(view)));
   }
+  wm::GetWindowState(view->GetWidget()->GetNativeWindow())
+      ->set_ignored_by_shelf(true);
   keyboard::KeyboardController* keyboard_controller =
       keyboard::KeyboardController::GetInstance();
   if (keyboard_controller)

ash/app_list/app_list_presenter_delegate_unittest.cc

@@ -699,6 +699,8 @@ TEST_F(AppListPresenterDelegateTest,
   app_list_presenter_impl()->Show(GetPrimaryDisplayId());
   EXPECT_TRUE(app_list::features::IsFullscreenAppListEnabled());
   EXPECT_FALSE(GetPrimaryShelf()->IsHorizontalAlignment());
+  // TODO(muyuanli): This should be SHELF_BACKGROUND_OVERLAP but the test
+  // construction code is not quite correct. See crbug.com/742461.
   EXPECT_EQ(GetPrimaryShelf()->shelf_layout_manager()->GetShelfBackgroundType(),
             SHELF_BACKGROUND_DEFAULT);
 }

ash/shelf/shelf_layout_manager_unittest.cc

@@ -9,6 +9,7 @@
 #include "ash/focus_cycler.h"
 #include "ash/public/cpp/config.h"
 #include "ash/public/cpp/shell_window_ids.h"
+#include "ash/root_window_controller.h"
 #include "ash/session/session_controller.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_constants.h"
@@ -1559,6 +1560,24 @@ TEST_F(ShelfLayoutManagerTest, AutohideShelfForAutohideWhenActiveWindow) {
       ->set_autohide_shelf_when_maximized_or_fullscreen(false);
   widget_two->Activate();
   EXPECT_EQ(SHELF_VISIBLE, shelf->GetVisibilityState());
+
+  wm::GetWindowState(window_two)
+      ->set_autohide_shelf_when_maximized_or_fullscreen(true);
+  window_two->SetProperty(aura::client::kAlwaysOnTopKey, true);
+
+  auto* shelf_window = shelf->GetWindow();
+  aura::Window* container = shelf_window->GetRootWindow()->GetChildById(
+      kShellWindowId_AlwaysOnTopContainer);
+  auto iter = std::find(container->children().begin(),
+                        container->children().end(), window_two);
+  EXPECT_NE(iter, container->children().end());
+
+  widget_two->Maximize();
+  EXPECT_EQ(SHELF_AUTO_HIDE, shelf->GetVisibilityState());
+
+  wm::WorkspaceWindowState window_state =
+      RootWindowController::ForWindow(shelf_window)->GetWorkspaceWindowState();
+  EXPECT_EQ(wm::WORKSPACE_WINDOW_STATE_MAXIMIZED, window_state);
 }
 
 TEST_F(ShelfLayoutManagerTest, ShelfFlickerOnTrayActivation) {

ash/wm/workspace_controller.cc

@@ -9,8 +9,10 @@
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf.h"
+#include "ash/shell.h"
 #include "ash/shell_port.h"
 #include "ash/wm/fullscreen_window_finder.h"
+#include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/wm_window_animations.h"
 #include "ash/wm/workspace/backdrop_controller.h"
@@ -61,11 +63,11 @@ wm::WorkspaceWindowState WorkspaceController::GetWindowState() const {
 
   const gfx::Rect shelf_bounds(Shelf::ForWindow(viewport_)->GetIdealBounds());
   bool window_overlaps_launcher = false;
-  // The default container may contain windows that may overlap the launcher
-  // shelf and affect its transparency.
-  aura::Window* container =
-      viewport_->GetRootWindow()->GetChildById(kShellWindowId_DefaultContainer);
-  for (aura::Window* window : container->children()) {
+  auto mru_list = Shell::Get()->mru_window_tracker()->BuildMruWindowList();
+
+  for (aura::Window* window : mru_list) {
+    if (window->GetRootWindow() != viewport_->GetRootWindow())
+      continue;
     wm::WindowState* window_state = wm::GetWindowState(window);
     if (window_state->ignored_by_shelf() ||
         (window->layer() && !window->layer()->GetTargetVisibility())) {