Relayout windows in overview when display size changes.

ash/wm/overview/window_overview.cc

Index: ash/wm/overview/window_overview.cc
diff --git a/ash/wm/overview/window_overview.cc b/ash/wm/overview/window_overview.cc
index da615f755825d499a2b8ac56e3706114ea6c98ee..ec5efc76a6bc8036a206850c48ed95be0ac1607e 100644
--- a/ash/wm/overview/window_overview.cc
+++ b/ash/wm/overview/window_overview.cc
@@ -22,6 +22,7 @@
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/events/event.h"
+#include "ui/gfx/screen.h"
 #include "ui/views/background.h"
 #include "ui/views/widget/widget.h"
 
@@ -132,7 +133,7 @@ WindowOverview::WindowOverview(WindowSelector* window_selector,
        iter != windows_->end(); ++iter) {
     (*iter)->PrepareForOverview();
   }
-  PositionWindows();
+  PositionWindows(/* animate */ true);
   DCHECK(!windows_->empty());
   cursor_client_ = aura::client::GetCursorClient(
       windows_->front()->GetRootWindow());
@@ -146,6 +147,7 @@ WindowOverview::WindowOverview(WindowSelector* window_selector,
     cursor_client_->LockCursor();
   }
   shell->PrependPreTargetHandler(this);
+  shell->GetScreen()->AddObserver(this);
   shell->metrics()->RecordUserMetricsAction(UMA_WINDOW_OVERVIEW);
   HideAndTrackNonOverviewWindows();
 }
@@ -167,6 +169,7 @@ WindowOverview::~WindowOverview() {
     cursor_client_->UnlockCursor();
   ash::Shell* shell = ash::Shell::GetInstance();
   shell->RemovePreTargetHandler(this);
+  shell->GetScreen()->RemoveObserver(this);
   UMA_HISTOGRAM_MEDIUM_TIMES(
       "Ash.WindowSelector.TimeInOverview",
       base::Time::Now() - overview_start_time_);
@@ -242,12 +245,12 @@ void WindowOverview::SetSelection(size_t index) {
 }
 
 void WindowOverview::OnWindowsChanged() {
-  PositionWindows();
+  PositionWindows(/* animate */ true);
 }
 
 void WindowOverview::MoveToSingleRootWindow(aura::Window* root_window) {
   single_root_window_ = root_window;
-  PositionWindows();
+  PositionWindows(/* animate */ true);
 }
 
 void WindowOverview::OnKeyEvent(ui::KeyEvent* event) {
@@ -298,6 +301,16 @@ void WindowOverview::OnTouchEvent(ui::TouchEvent* event) {
   window_selector_->SelectWindow(target);
 }
 
+void WindowOverview::OnDisplayBoundsChanged(const gfx::Display& display) {
+  PositionWindows(/* animate */ false);
+}
+
+void WindowOverview::OnDisplayAdded(const gfx::Display& display) {
+}
+
+void WindowOverview::OnDisplayRemoved(const gfx::Display& display) {
+}
+
 aura::Window* WindowOverview::GetEventTarget(ui::LocatedEvent* event) {
   aura::Window* target = static_cast<aura::Window*>(event->target());
   // If the target window doesn't actually contain the event location (i.e.
@@ -358,34 +371,36 @@ void WindowOverview::HideAndTrackNonOverviewWindows() {
   }
 }
 
-void WindowOverview::PositionWindows() {
+void WindowOverview::PositionWindows(bool animate) {
   if (single_root_window_) {
     std::vector<WindowSelectorItem*> windows;
     for (WindowSelectorItemList::iterator iter = windows_->begin();
          iter != windows_->end(); ++iter) {
       windows.push_back(*iter);
     }
-    PositionWindowsOnRoot(single_root_window_, windows);
+    PositionWindowsOnRoot(single_root_window_, windows, animate);
   } else {
     aura::Window::Windows root_window_list = Shell::GetAllRootWindows();
     for (size_t i = 0; i < root_window_list.size(); ++i)
-      PositionWindowsFromRoot(root_window_list[i]);
+      PositionWindowsFromRoot(root_window_list[i], animate);
   }
 }
 
-void WindowOverview::PositionWindowsFromRoot(aura::Window* root_window) {
+void WindowOverview::PositionWindowsFromRoot(aura::Window* root_window,
+                                             bool animate) {
   std::vector<WindowSelectorItem*> windows;
   for (WindowSelectorItemList::iterator iter = windows_->begin();
        iter != windows_->end(); ++iter) {
     if ((*iter)->GetRootWindow() == root_window)
       windows.push_back(*iter);
   }
-  PositionWindowsOnRoot(root_window, windows);
+  PositionWindowsOnRoot(root_window, windows, animate);
 }
 
 void WindowOverview::PositionWindowsOnRoot(
     aura::Window* root_window,
-    const std::vector<WindowSelectorItem*>& windows) {
+    const std::vector<WindowSelectorItem*>& windows,
+    bool animate) {
   if (windows.empty())
     return;
 
@@ -422,7 +437,7 @@ void WindowOverview::PositionWindowsOnRoot(
                             window_size.width(),
                             window_size.height());
     target_bounds.Inset(kWindowMargin, kWindowMargin);
-    windows[i]->SetBounds(root_window, target_bounds);
+    windows[i]->SetBounds(root_window, target_bounds, animate);
   }
 }