Revert of Use platform's device scale factor for cursor (https://codereview.chromium.org/226293005/)

Reason for revert:
There are no resize cursors in DevTools on Linux Aura anymore.

Original issue's description:
> Use platform's device scale factor for cursor instead of gfx::Display because gfx::Display's DSF may differ from
> platform's one when UI scaling is used.
> 
> BUG=361672
> TEST=covered by unit test
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=265592

TBR=tdanderson@chromium.org,sky@chromium.org,oshima@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=361672

Review URL: https://codereview.chromium.org/249303002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@265625 0039d316-1c4b-4281-b951-d872f2087c98

12 files changed, 87 insertions, 116 deletions

diff --git a/ash/display/display_controller_unittest.cc b/ash/display/display_controller_unittest.cc
index 95b7af6..3da1368 100644
--- a/ash/display/display_controller_unittest.cc
+++ b/ash/display/display_controller_unittest.cc
@@ -935,11 +935,11 @@ TEST_F(DisplayControllerTest, CursorDeviceScaleFactorSwapPrimary) {
   EXPECT_EQ(1.0f, primary_root->GetHost()->compositor()->
       device_scale_factor());
   primary_root->MoveCursorTo(gfx::Point(50, 50));
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(1.0f, test_api.GetDisplay().device_scale_factor());
   EXPECT_EQ(2.0f, secondary_root->GetHost()->compositor()->
       device_scale_factor());
   secondary_root->MoveCursorTo(gfx::Point(50, 50));
-  EXPECT_EQ(2.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(2.0f, test_api.GetDisplay().device_scale_factor());
 
   // Switch primary and secondary
   display_controller->SetPrimaryDisplay(secondary_display);
@@ -949,23 +949,23 @@ TEST_F(DisplayControllerTest, CursorDeviceScaleFactorSwapPrimary) {
   EXPECT_EQ(1.0f, secondary_root->GetHost()->compositor()->
       device_scale_factor());
   secondary_root->MoveCursorTo(gfx::Point(50, 50));
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(1.0f, test_api.GetDisplay().device_scale_factor());
   primary_root->MoveCursorTo(gfx::Point(50, 50));
   EXPECT_EQ(2.0f, primary_root->GetHost()->compositor()->
       device_scale_factor());
-  EXPECT_EQ(2.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(2.0f, test_api.GetDisplay().device_scale_factor());
 
   // Deleting 2nd display.
   UpdateDisplay("200x200");
   RunAllPendingInMessageLoop();  // RootWindow is deleted in a posted task.
 
   // Cursor's device scale factor should be updated even without moving cursor.
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(1.0f, test_api.GetDisplay().device_scale_factor());
 
   primary_root->MoveCursorTo(gfx::Point(50, 50));
   EXPECT_EQ(1.0f, primary_root->GetHost()->compositor()->
       device_scale_factor());
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(1.0f, test_api.GetDisplay().device_scale_factor());
 }
 
 TEST_F(DisplayControllerTest, OverscanInsets) {
diff --git a/ash/display/display_manager.cc b/ash/display/display_manager.cc
index 7f6d713..83d747a 100644
--- a/ash/display/display_manager.cc
+++ b/ash/display/display_manager.cc
@@ -838,8 +838,6 @@ bool DisplayManager::IsMirrored() const {
 }
 
 const DisplayInfo& DisplayManager::GetDisplayInfo(int64 display_id) const {
-  DCHECK_NE(gfx::Display::kInvalidDisplayID, display_id);
-
   std::map<int64, DisplayInfo>::const_iterator iter =
       display_info_.find(display_id);
   CHECK(iter != display_info_.end()) << display_id;
diff --git a/ash/display/mouse_cursor_event_filter_unittest.cc b/ash/display/mouse_cursor_event_filter_unittest.cc
index 3325d37..1b34456 100644
--- a/ash/display/mouse_cursor_event_filter_unittest.cc
+++ b/ash/display/mouse_cursor_event_filter_unittest.cc
@@ -368,11 +368,11 @@ TEST_F(MouseCursorEventFilterTest, CursorDeviceScaleFactor) {
   test::CursorManagerTestApi cursor_test_api(
       Shell::GetInstance()->cursor_manager());
 
-  EXPECT_EQ(1.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(1.0f, cursor_test_api.GetDisplay().device_scale_factor());
   WarpMouseCursorIfNecessary(root_windows[0], gfx::Point(399, 200));
-  EXPECT_EQ(2.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(2.0f, cursor_test_api.GetDisplay().device_scale_factor());
   WarpMouseCursorIfNecessary(root_windows[1], gfx::Point(400, 200));
-  EXPECT_EQ(1.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(1.0f, cursor_test_api.GetDisplay().device_scale_factor());
 }
 
 }  // namespace ash
diff --git a/ash/display/screen_ash.cc b/ash/display/screen_ash.cc
index 9d42e49e..d32deb8 100644
--- a/ash/display/screen_ash.cc
+++ b/ash/display/screen_ash.cc
@@ -234,8 +234,7 @@ gfx::Display ScreenAsh::GetDisplayNearestWindow(gfx::NativeView window) const {
     return GetPrimaryDisplay();
   const RootWindowSettings* rws = GetRootWindowSettings(root_window);
   if (rws->shutdown)
-    return GetPrimaryDisplay();
-
+    return gfx::Display(1);
   int64 id = rws->display_id;
   // if id is |kInvaildDisplayID|, it's being deleted.
   DCHECK(id != gfx::Display::kInvalidDisplayID);
diff --git a/ash/test/cursor_manager_test_api.cc b/ash/test/cursor_manager_test_api.cc
index 4ff7cf7..22aa261 100644
--- a/ash/test/cursor_manager_test_api.cc
+++ b/ash/test/cursor_manager_test_api.cc
@@ -31,16 +31,9 @@ gfx::NativeCursor CursorManagerTestApi::GetCurrentCursor() const {
   return cursor_manager_->GetCursor();
 }
 
-gfx::Display::Rotation
-CursorManagerTestApi::GetCurrentCursorRotation() const {
+gfx::Display CursorManagerTestApi::GetDisplay() const {
   return ShellTestApi(Shell::GetInstance()).ash_native_cursor_manager()->
-      image_cursors_->GetRotation();
-}
-
-float
-CursorManagerTestApi::GetCurrentCursorScale() const {
-  return ShellTestApi(Shell::GetInstance()).ash_native_cursor_manager()->
-      image_cursors_->GetScale();
+      image_cursors_->GetDisplay();
 }
 
 }  // namespace test
diff --git a/ash/test/cursor_manager_test_api.h b/ash/test/cursor_manager_test_api.h
index fce98ca..1b9c6b8 100644
--- a/ash/test/cursor_manager_test_api.h
+++ b/ash/test/cursor_manager_test_api.h
@@ -7,9 +7,12 @@
 
 #include "base/basictypes.h"
 #include "ui/base/cursor/cursor.h"
-#include "ui/gfx/display.h"
 #include "ui/gfx/native_widget_types.h"
 
+namespace gfx {
+class Display;
+}
+
 namespace wm {
 class CursorManager;
 }
@@ -25,8 +28,7 @@ class CursorManagerTestApi {
 
   ui::CursorSetType GetCurrentCursorSet() const;
   gfx::NativeCursor GetCurrentCursor() const;
-  gfx::Display::Rotation GetCurrentCursorRotation() const;
-  float GetCurrentCursorScale() const;
+  gfx::Display GetDisplay() const;
 
  private:
   ::wm::CursorManager* cursor_manager_;
diff --git a/ash/wm/ash_native_cursor_manager.cc b/ash/wm/ash_native_cursor_manager.cc
index e78eb94..98078ac 100644
--- a/ash/wm/ash_native_cursor_manager.cc
+++ b/ash/wm/ash_native_cursor_manager.cc
@@ -95,7 +95,8 @@ void AshNativeCursorManager::SetCursor(
       new_cursor.SetPlatformCursor(invisible_cursor.platform());
     }
   }
-  new_cursor.set_device_scale_factor(image_cursors_->GetScale());
+  new_cursor.set_device_scale_factor(
+      image_cursors_->GetDisplay().device_scale_factor());
 
   delegate->CommitCursor(new_cursor);
 
diff --git a/ash/wm/ash_native_cursor_manager_interactive_uitest.cc b/ash/wm/ash_native_cursor_manager_interactive_uitest.cc
index 83df158..5eee024 100644
--- a/ash/wm/ash_native_cursor_manager_interactive_uitest.cc
+++ b/ash/wm/ash_native_cursor_manager_interactive_uitest.cc
@@ -102,10 +102,10 @@ TEST_F(AshNativeCursorManagerTest, MAYBE_CursorChangeOnEnterNotify) {
   display_manager->OnNativeDisplaysChanged(display_info_list);
 
   MoveMouseSync(Shell::GetAllRootWindows()[0], 10, 10);
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(1.0f, test_api.GetDisplay().device_scale_factor());
 
   MoveMouseSync(Shell::GetAllRootWindows()[0], 600, 10);
-  EXPECT_EQ(2.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(2.0f, test_api.GetDisplay().device_scale_factor());
 }
 
 }  // namespace ash
diff --git a/ash/wm/ash_native_cursor_manager_unittest.cc b/ash/wm/ash_native_cursor_manager_unittest.cc
index 5713fe3..812601f 100644
--- a/ash/wm/ash_native_cursor_manager_unittest.cc
+++ b/ash/wm/ash_native_cursor_manager_unittest.cc
@@ -4,8 +4,6 @@
 
 #include "ash/wm/ash_native_cursor_manager.h"
 
-#include "ash/display/display_info.h"
-#include "ash/display/display_manager.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/cursor_manager_test_api.h"
@@ -56,16 +54,18 @@ typedef test::AshTestBase AshNativeCursorManagerTest;
 TEST_F(AshNativeCursorManagerTest, LockCursor) {
   ::wm::CursorManager* cursor_manager = Shell::GetInstance()->cursor_manager();
   CursorManagerTestApi test_api(cursor_manager);
-
+  gfx::Display display(0);
 #if defined(OS_WIN)
   ui::CursorLoaderWin::SetCursorResourceModule(L"ash_unittests.exe");
 #endif
   cursor_manager->SetCursor(ui::kCursorCopy);
   EXPECT_EQ(ui::kCursorCopy, test_api.GetCurrentCursor().native_type());
-  UpdateDisplay("800x800*2/r");
-  EXPECT_EQ(2.0f, test_api.GetCurrentCursor().device_scale_factor());
+  display.set_device_scale_factor(2.0f);
+  display.set_rotation(gfx::Display::ROTATE_90);
+  cursor_manager->SetDisplay(display);
+  EXPECT_EQ(2.0f, test_api.GetDisplay().device_scale_factor());
   EXPECT_EQ(ui::CURSOR_SET_NORMAL, test_api.GetCurrentCursorSet());
-  EXPECT_EQ(gfx::Display::ROTATE_90, test_api.GetCurrentCursorRotation());
+  EXPECT_EQ(gfx::Display::ROTATE_90, test_api.GetDisplay().rotation());
   EXPECT_TRUE(test_api.GetCurrentCursor().platform());
 
   cursor_manager->LockCursor();
@@ -85,16 +85,18 @@ TEST_F(AshNativeCursorManagerTest, LockCursor) {
   EXPECT_EQ(ui::kCursorCopy, test_api.GetCurrentCursor().native_type());
 
   // Device scale factor and rotation do change even while cursor is locked.
-  UpdateDisplay("800x800/u");
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
-  EXPECT_EQ(gfx::Display::ROTATE_180, test_api.GetCurrentCursorRotation());
+  display.set_device_scale_factor(1.0f);
+  display.set_rotation(gfx::Display::ROTATE_180);
+  cursor_manager->SetDisplay(display);
+  EXPECT_EQ(1.0f, test_api.GetDisplay().device_scale_factor());
+  EXPECT_EQ(gfx::Display::ROTATE_180, test_api.GetDisplay().rotation());
 
   cursor_manager->UnlockCursor();
   EXPECT_FALSE(cursor_manager->IsCursorLocked());
 
   // Cursor type changes to the one specified while cursor is locked.
   EXPECT_EQ(ui::kCursorPointer, test_api.GetCurrentCursor().native_type());
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
+  EXPECT_EQ(1.0f, test_api.GetDisplay().device_scale_factor());
   EXPECT_TRUE(test_api.GetCurrentCursor().platform());
 }
 
@@ -131,47 +133,18 @@ TEST_F(AshNativeCursorManagerTest, SetCursorSet) {
 TEST_F(AshNativeCursorManagerTest, SetDeviceScaleFactorAndRotation) {
   ::wm::CursorManager* cursor_manager = Shell::GetInstance()->cursor_manager();
   CursorManagerTestApi test_api(cursor_manager);
-  UpdateDisplay("800x100*2");
-  EXPECT_EQ(2.0f, test_api.GetCurrentCursor().device_scale_factor());
-  EXPECT_EQ(gfx::Display::ROTATE_0, test_api.GetCurrentCursorRotation());
-
-  UpdateDisplay("800x100/l");
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
-  EXPECT_EQ(gfx::Display::ROTATE_270, test_api.GetCurrentCursorRotation());
-}
 
-TEST_F(AshNativeCursorManagerTest, UIScaleShouldNotChangeCursor) {
-  int64 display_id = Shell::GetScreen()->GetPrimaryDisplay().id();
-  gfx::Display::SetInternalDisplayId(display_id);
-
-  ::wm::CursorManager* cursor_manager = Shell::GetInstance()->cursor_manager();
-  CursorManagerTestApi test_api(cursor_manager);
-  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
-
-  DisplayInfo::SetAllowUpgradeToHighDPI(false);
-  display_manager->SetDisplayUIScale(display_id, 0.5f);
-  EXPECT_EQ(1.0f,
-            Shell::GetScreen()->GetPrimaryDisplay().device_scale_factor());
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
-
-  display_manager->SetDisplayUIScale(display_id, 1.0f);
-
-  DisplayInfo::SetAllowUpgradeToHighDPI(true);
-  // 1x display should keep using 1x cursor even if the DSF is upgraded to 2x.
-  display_manager->SetDisplayUIScale(display_id, 0.5f);
-  EXPECT_EQ(2.0f,
-            Shell::GetScreen()->GetPrimaryDisplay().device_scale_factor());
-  EXPECT_EQ(1.0f, test_api.GetCurrentCursor().device_scale_factor());
-
-  // 2x display should keep using 2x cursor regardless of the UI scale.
-  UpdateDisplay("800x800*2");
-  EXPECT_EQ(2.0f,
-            Shell::GetScreen()->GetPrimaryDisplay().device_scale_factor());
-  EXPECT_EQ(2.0f, test_api.GetCurrentCursor().device_scale_factor());
-  display_manager->SetDisplayUIScale(display_id, 2.0f);
-  EXPECT_EQ(1.0f,
-            Shell::GetScreen()->GetPrimaryDisplay().device_scale_factor());
-  EXPECT_EQ(2.0f, test_api.GetCurrentCursor().device_scale_factor());
+  gfx::Display display(0);
+  display.set_device_scale_factor(2.0f);
+  cursor_manager->SetDisplay(display);
+  EXPECT_EQ(2.0f, test_api.GetDisplay().device_scale_factor());
+  EXPECT_EQ(gfx::Display::ROTATE_0, test_api.GetDisplay().rotation());
+
+  display.set_device_scale_factor(1.0f);
+  display.set_rotation(gfx::Display::ROTATE_270);
+  cursor_manager->SetDisplay(display);
+  EXPECT_EQ(1.0f, test_api.GetDisplay().device_scale_factor());
+  EXPECT_EQ(gfx::Display::ROTATE_270, test_api.GetDisplay().rotation());
 }
 
 TEST_F(AshNativeCursorManagerTest, DisabledQueryMouseLocation) {
diff --git a/ash/wm/drag_window_resizer_unittest.cc b/ash/wm/drag_window_resizer_unittest.cc
index 369a285..dbb4da0 100644
--- a/ash/wm/drag_window_resizer_unittest.cc
+++ b/ash/wm/drag_window_resizer_unittest.cc
@@ -494,13 +494,13 @@ TEST_F(DragWindowResizerTest, CursorDeviceScaleFactor) {
     // Grab (0, 0) of the window.
     scoped_ptr<WindowResizer> resizer(CreateDragWindowResizer(
         window_.get(), gfx::Point(), HTCAPTION));
-    EXPECT_EQ(1.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+    EXPECT_EQ(1.0f, cursor_test_api.GetDisplay().device_scale_factor());
     ASSERT_TRUE(resizer.get());
     resizer->Drag(CalculateDragPoint(*resizer, 399, 200), 0);
     WarpMouseCursorIfNecessary(root_windows[0], gfx::Point(399, 200));
-    EXPECT_EQ(2.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+    EXPECT_EQ(2.0f, cursor_test_api.GetDisplay().device_scale_factor());
     resizer->CompleteDrag();
-    EXPECT_EQ(2.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+    EXPECT_EQ(2.0f, cursor_test_api.GetDisplay().device_scale_factor());
   }
 
   // Move window from the root window with 2.0 device scale factor to the root
@@ -518,13 +518,13 @@ TEST_F(DragWindowResizerTest, CursorDeviceScaleFactor) {
     // Grab (0, 0) of the window.
     scoped_ptr<WindowResizer> resizer(CreateDragWindowResizer(
         window_.get(), gfx::Point(), HTCAPTION));
-    EXPECT_EQ(2.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+    EXPECT_EQ(2.0f, cursor_test_api.GetDisplay().device_scale_factor());
     ASSERT_TRUE(resizer.get());
     resizer->Drag(CalculateDragPoint(*resizer, -200, 200), 0);
     WarpMouseCursorIfNecessary(root_windows[1], gfx::Point(400, 200));
-    EXPECT_EQ(1.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+    EXPECT_EQ(1.0f, cursor_test_api.GetDisplay().device_scale_factor());
     resizer->CompleteDrag();
-    EXPECT_EQ(1.0f, cursor_test_api.GetCurrentCursor().device_scale_factor());
+    EXPECT_EQ(1.0f, cursor_test_api.GetDisplay().device_scale_factor());
   }
 }
 
diff --git a/ash/wm/image_cursors.cc b/ash/wm/image_cursors.cc
index 2a41375..e63bece 100644
--- a/ash/wm/image_cursors.cc
+++ b/ash/wm/image_cursors.cc
@@ -6,9 +6,6 @@
 
 #include <float.h>
 
-#include "ash/display/display_info.h"
-#include "ash/display/display_manager.h"
-#include "ash/shell.h"
 #include "base/logging.h"
 #include "base/strings/string16.h"
 #include "ui/base/cursor/cursor.h"
@@ -59,54 +56,41 @@ const int kAnimatedCursorIds[] = {
   ui::kCursorProgress
 };
 
-ImageCursors::ImageCursors() : cursor_set_(ui::CURSOR_SET_NORMAL) {
+ImageCursors::ImageCursors() : scale_(1.f), cursor_set_(ui::CURSOR_SET_NORMAL) {
 }
 
 ImageCursors::~ImageCursors() {
 }
 
-float ImageCursors::GetScale() const {
+gfx::Display ImageCursors::GetDisplay() const {
   if (!cursor_loader_) {
     NOTREACHED();
     // Returning default on release build as it's not serious enough to crash
     // even if this ever happens.
-    return 1.0f;
+    return gfx::Display();
   }
-  return cursor_loader_->scale();
-}
-
-gfx::Display::Rotation ImageCursors::GetRotation() const {
-  if (!cursor_loader_) {
-    NOTREACHED();
-    // Returning default on release build as it's not serious enough to crash
-    // even if this ever happens.
-    return gfx::Display::ROTATE_0;
-  }
-  return cursor_loader_->rotation();
+  return cursor_loader_->display();
 }
 
 bool ImageCursors::SetDisplay(const gfx::Display& display) {
-  DCHECK(display.is_valid());
-  // Use the platform's device scale factor instead of display's
-  // that might have been adjusted for UI scale.
-  float scale_factor = Shell::GetInstance()->display_manager()->
-      GetDisplayInfo(display.id()).device_scale_factor();
-
+  float device_scale_factor = display.device_scale_factor();
   if (!cursor_loader_) {
     cursor_loader_.reset(ui::CursorLoader::Create());
-  } else if (cursor_loader_->rotation() == display.rotation() &&
-             cursor_loader_->scale() == scale_factor) {
+    cursor_loader_->set_scale(scale_);
+  } else if (cursor_loader_->display().rotation() == display.rotation() &&
+             cursor_loader_->display().device_scale_factor() ==
+             device_scale_factor) {
     return false;
   }
 
-  cursor_loader_->set_rotation(display.rotation());
-  cursor_loader_->set_scale(scale_factor);
+  cursor_loader_->set_display(display);
   ReloadCursors();
   return true;
 }
 
 void ImageCursors::ReloadCursors() {
-  float device_scale_factor = cursor_loader_->scale();
+  const gfx::Display& display = cursor_loader_->display();
+  float device_scale_factor = display.device_scale_factor();
 
   cursor_loader_->UnloadAll();
 
@@ -137,6 +121,20 @@ void ImageCursors::ReloadCursors() {
   }
 }
 
+void ImageCursors::SetScale(float scale) {
+  if (scale < FLT_EPSILON) {
+    NOTREACHED() << "Scale must be bigger than 0.";
+    scale = 1.0f;
+  }
+
+  scale_ = scale;
+
+  if (cursor_loader_.get()) {
+    cursor_loader_->set_scale(scale);
+    ReloadCursors();
+  }
+}
+
 void ImageCursors::SetCursorSet(ui::CursorSetType cursor_set) {
   if (cursor_set_ == cursor_set)
     return;
diff --git a/ash/wm/image_cursors.h b/ash/wm/image_cursors.h
index 1a75f40..55bc34c 100644
--- a/ash/wm/image_cursors.h
+++ b/ash/wm/image_cursors.h
@@ -9,9 +9,12 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 #include "ui/base/cursor/cursor.h"
-#include "ui/gfx/display.h"
 #include "ui/gfx/native_widget_types.h"
 
+namespace gfx {
+class Display;
+}
+
 namespace ui {
 class CursorLoader;
 }
@@ -25,9 +28,9 @@ class ASH_EXPORT ImageCursors {
   ImageCursors();
   ~ImageCursors();
 
-  // Returns the scale and rotation of the currently loaded cursor.
-  float GetScale() const;
-  gfx::Display::Rotation GetRotation() const;
+  // Returns the display the cursors are loaded for. The display must
+  // be set by SetDisplay before using this.
+  gfx::Display GetDisplay() const;
 
   // Sets the display the cursors are loaded for. The device scale factor
   // determines the size of the image to load, and the rotation of the display
@@ -35,6 +38,9 @@ class ASH_EXPORT ImageCursors {
   // Returns true if the cursor image is reloaded.
   bool SetDisplay(const gfx::Display& display);
 
+  // Sets the scale of the mouse cursor icon.
+  void SetScale(float scale);
+
   // Sets the type of the mouse cursor icon.
   void SetCursorSet(ui::CursorSetType cursor_set);
 
@@ -46,6 +52,7 @@ class ASH_EXPORT ImageCursors {
   void ReloadCursors();
 
   scoped_ptr<ui::CursorLoader> cursor_loader_;
+  float scale_;
   ui::CursorSetType cursor_set_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageCursors);