Avoids updating dock alignment when drag is cancelled

ash/wm/dock/docked_window_resizer_unittest.cc

 // Copyright (c) 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 "ash/wm/dock/docked_window_resizer.h"
 
 #include "ash/ash_switches.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_ash.h"
 #include "ash/shelf/shelf.h"
@@ skipping 606 matching lines @@
   DragEnd();
   EXPECT_EQ(internal::kShellWindowId_DefaultContainer,
             window->parent()->id());
 }
 
 // Tests that reverting drag restores undocked state if a window was not docked.
 TEST_P(DockedWindowResizerTest, RevertDockedDragRevertsAttachment) {
   if (!SupportsHostWindowResize())
     return;
   scoped_ptr<aura::Window> window(CreateTestWindow(gfx::Rect(0, 0, 201, 201)));
+  aura::Window* dock_container = Shell::GetContainer(
+      window->GetRootWindow(),
+      kShellWindowId_DockedContainer);
+  DockedWindowLayoutManager* manager =
+      static_cast<DockedWindowLayoutManager*>(dock_container->layout_manager());
   int previous_container_id = window->parent()->id();
   // Drag the window out but revert the drag
   ASSERT_NO_FATAL_FAILURE(DragStart(window.get()));
   DragMove(-50 - window->bounds().x(), 50 - window->bounds().y());
   EXPECT_EQ(CorrectContainerIdDuringDrag(), window->parent()->id());
   DragRevert();
   EXPECT_EQ(previous_container_id, window->parent()->id());
+  EXPECT_EQ(DOCKED_ALIGNMENT_NONE, docked_alignment(manager));
+
+  // Drag a window to the left so that it overlaps the screen edge.
+  ASSERT_NO_FATAL_FAILURE(DragStartAtOffsetFromWindowOrigin(
+      window.get(),
+      window->bounds().width()/2 + 10,
+      0));
+  DragMove(-50 - window->bounds().x(), 50 - window->bounds().y());
+  DragEnd();
+  // The window now overlaps the left screen edge but is not docked.
+  EXPECT_EQ(kShellWindowId_DefaultContainer, window->parent()->id());
+  EXPECT_EQ(DOCKED_ALIGNMENT_NONE, docked_alignment(manager));
+  EXPECT_LT(window->bounds().x(), 0);
+  EXPECT_GT(window->bounds().right(), 0);
+
+  // Drag the window further left and revert the drag.
+  ASSERT_NO_FATAL_FAILURE(DragStartAtOffsetFromWindowOrigin(
+      window.get(),
+      window->bounds().width()/2 + 10,
+      0));
+  DragMove(-10, 10);
+  DragRevert();
+  // The window should be in default container and not docked.
+  EXPECT_EQ(kShellWindowId_DefaultContainer, window->parent()->id());
+  // Docked area alignment should be cleared.
+  EXPECT_EQ(DOCKED_ALIGNMENT_NONE, docked_alignment(manager));
 }
 
 // Move a docked window to the second display
 TEST_P(DockedWindowResizerTest, DragAcrossDisplays) {
   if (!SupportsMultipleDisplays())
     return;
 
   UpdateDisplay("800x800,800x800");
   aura::Window::Windows root_windows = Shell::GetAllRootWindows();
   EXPECT_EQ(2, static_cast<int>(root_windows.size()));
@@ skipping 840 matching lines @@
   EXPECT_TRUE(window_state->IsSnapped());
 }
 
 // Tests run twice - on both panels and normal windows
 INSTANTIATE_TEST_CASE_P(NormalOrPanel,
                         DockedWindowResizerTest,
                         testing::Values(ui::wm::WINDOW_TYPE_NORMAL,
                                         ui::wm::WINDOW_TYPE_PANEL));
 }  // namespace internal
 }  // namespace ash