Windows docking should get triggered by pressing against the screen edge

ash/wm/workspace/workspace_window_resizer_unittest.cc

 // Copyright (c) 2012 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/workspace/workspace_window_resizer.h"
 
 #include "ash/ash_constants.h"
 #include "ash/ash_switches.h"
 #include "ash/display/display_controller.h"
 #include "ash/root_window_controller.h"
@@ skipping 1825 matching lines @@
   if (!SupportsMultipleDisplays())
     return;
 
   UpdateDisplay("500x400,500x400");
   window_->SetBoundsInScreen(gfx::Rect(0, 0, 50, 60),
                              Shell::GetScreen()->GetPrimaryDisplay());
   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
   EXPECT_EQ(root_windows[0], window_->GetRootWindow());
 
   scoped_ptr<WorkspaceWindowResizer> resizer(WorkspaceWindowResizer::Create(
-      window_.get(), gfx::Point(), HTCAPTION,
+      window_.get(), gfx::Point(0,0), HTCAPTION,
       aura::client::WINDOW_MOVE_SOURCE_MOUSE, empty_windows()));
   ASSERT_TRUE(resizer.get());
   EXPECT_FALSE(resizer->snap_phantom_window_controller_.get());
 
   // The pointer is on the edge but not shared. The snap phantom window
   // controller should be non-NULL.
-  resizer->Drag(CalculateDragPoint(*resizer, 499, 0), 0);
+  resizer->Drag(CalculateDragPoint(*resizer, -1, 0), 0);
   EXPECT_TRUE(resizer->snap_phantom_window_controller_.get());
   PhantomWindowController* phantom_controller(
       resizer->snap_phantom_window_controller_.get());
 
   // phantom widget only in the left screen.
   phantom_controller->Show(gfx::Rect(100, 100, 50, 60));
   EXPECT_TRUE(phantom_controller->phantom_widget_);
   EXPECT_FALSE(phantom_controller->phantom_widget_start_);
   EXPECT_EQ(
       root_windows[0],
@@ skipping 71 matching lines @@
   RunAnimationTillComplete(phantom_controller->animation_.get());
 
   // Hide phantom controller. Both widgets should close.
   phantom_controller->Hide();
   EXPECT_FALSE(phantom_controller->phantom_widget_);
   EXPECT_FALSE(phantom_controller->phantom_widget_start_);
 }
 
 }  // namespace internal
 }  // namespace ash