Undo all existing overscan settings before updating to a new overscan settings (2nd)

ash/display/display_manager_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/display/display_manager.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
@@ skipping 216 matching lines @@
   display_manager()->SetOverscanInsets(
       display2.id(), gfx::Insets(13, 12, 11, 10));
   std::vector<gfx::Display> changed_displays = changed();
   EXPECT_EQ(1u, changed_displays.size());
   EXPECT_EQ(display2.id(), changed_displays[0].id());
   EXPECT_EQ("0,0 500x500",
             display_manager()->GetDisplayAt(0)->bounds_in_pixel().ToString());
   EXPECT_EQ("12,514 378x376",
             display_manager()->GetDisplayAt(1)->bounds_in_pixel().ToString());
 
+  // Make sure that SetOverscanInsets() is idempotent.
+  display_manager()->SetOverscanInsets(display1.id(), gfx::Insets());
+  display_manager()->SetOverscanInsets(
+      display2.id(), gfx::Insets(13, 12, 11, 10));
+  EXPECT_EQ("0,0 500x500",
+            display_manager()->GetDisplayAt(0)->bounds_in_pixel().ToString());
+  EXPECT_EQ("12,514 378x376",
+            display_manager()->GetDisplayAt(1)->bounds_in_pixel().ToString());
+
   display_manager()->SetOverscanInsets(
       display2.id(), gfx::Insets(10, 11, 12, 13));
   EXPECT_EQ("0,0 500x500",
             display_manager()->GetDisplayAt(0)->bounds_in_pixel().ToString());
   EXPECT_EQ("11,511 376x378",
             display_manager()->GetDisplayAt(1)->bounds_in_pixel().ToString());
 
   // Recreate a new 2nd display. It won't apply the overscan inset because the
   // new display has a different ID.
   UpdateDisplay("0+0-500x500");
@@ skipping 18 matching lines @@
   // HiDPI but overscan display. The specified insets size should be doubled.
   UpdateDisplay("0+0-500x500");
   UpdateDisplay("0+0-500x500,0+501-400x400*2");
   display_manager()->SetOverscanInsets(
       display_manager()->GetDisplayAt(1)->id(), gfx::Insets(4, 5, 6, 7));
   EXPECT_EQ("0,0 500x500",
             display_manager()->GetDisplayAt(0)->bounds_in_pixel().ToString());
   EXPECT_EQ("10,509 376x380",
             display_manager()->GetDisplayAt(1)->bounds_in_pixel().ToString());
   EXPECT_EQ("188x190", display_manager()->GetDisplayAt(1)->size().ToString());
+
+  // Make sure switching primary display applies the overscan offset only once.
+  ash::Shell::GetInstance()->display_controller()->SetPrimaryDisplay(
+      ScreenAsh::GetSecondaryDisplay());
+  EXPECT_EQ("0,0 500x500",
+            ScreenAsh::GetSecondaryDisplay().bounds_in_pixel().ToString());
+  EXPECT_EQ("10,509 376x380", gfx::Screen::GetNativeScreen()->
+            GetPrimaryDisplay().bounds_in_pixel().ToString());
 }
 
 TEST_F(DisplayManagerTest, MAYBE_ZeroOverscanInsets) {
   // Make sure the display change events is emitted for overscan inset changes.
   UpdateDisplay("0+0-500x500,0+501-400x400");
   ASSERT_EQ(2u, display_manager()->GetNumDisplays());
   int64 display2_id = display_manager()->GetDisplayAt(1)->id();
 
   reset();
   display_manager()->SetOverscanInsets(display2_id, gfx::Insets(0, 0, 0, 0));
@@ skipping 209 matching lines @@
   // OnNativeDisplaysChanged may change the display bounds.  Here makes sure
   // nothing changed if the exactly same displays are specified.
   display_manager()->OnNativeDisplaysChanged(displays);
   EXPECT_EQ("-500,0 500x500",
             FindDisplayForId(internal_display_id).bounds().ToString());
   EXPECT_EQ("0,0 100x100", FindDisplayForId(10).bounds().ToString());
 }
 
 }  // namespace internal
 }  // namespace ash