Add ScopedObjCClassSwizzler in base/mac, absorbs objc_method_swizzle and ScopedClassSwizzler

ui/events/cocoa/events_mac_unittest.mm

 // Copyright 2014 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 "ui/events/event_utils.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/scoped_cftyperef.h"
+#import "base/mac/scoped_objc_class_swizzler.h"
 #include "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/events/event_constants.h"
 #import "ui/events/test/cocoa_test_event_utils.h"
 #include "ui/gfx/point.h"
 #import "ui/gfx/test/ui_cocoa_test_helper.h"
 
 namespace {
 
 NSWindow* g_test_window = nil;
 
 }  // namespace
 
 // Mac APIs for creating test events are frustrating. Quartz APIs have, e.g.,
 // CGEventCreateMouseEvent() which can't set a window or modifier flags.
 // Cocoa APIs have +[NSEvent mouseEventWithType:..] which can't set
 // buttonNumber or scroll deltas. To work around this, these tests use some
 // Objective C magic to donate member functions to NSEvent temporarily.
 @interface MiddleMouseButtonNumberDonor : NSObject
 @end
 
 @interface TestWindowDonor : NSObject
 @end
 
 @implementation MiddleMouseButtonNumberDonor
-- (NSUInteger)buttonNumber { return 2; }
+- (NSInteger)buttonNumber { return 2; }
 @end
 
 @implementation TestWindowDonor
 - (NSWindow*)window { return g_test_window; }
 @end
 
 namespace ui {
 
 namespace {
 
 class EventsMacTest : public CocoaTest {
  public:
   EventsMacTest() {}
 
   gfx::Point Flip(gfx::Point window_location) {
     NSRect window_frame = [test_window() frame];
     CGFloat content_height =
         NSHeight([test_window() contentRectForFrameRect:window_frame]);
     window_location.set_y(content_height - window_location.y());
     return window_location;
   }
 
   void SwizzleMiddleMouseButton() {
     DCHECK(!swizzler_);
-    swizzler_.reset(new ScopedClassSwizzler(
+    swizzler_.reset(new base::mac::ScopedObjCClassSwizzler(
         [NSEvent class],
         [MiddleMouseButtonNumberDonor class],
         @selector(buttonNumber)));
   }
 
   void SwizzleTestWindow() {
     DCHECK(!g_test_window);
     DCHECK(!swizzler_);
     g_test_window = test_window();
-    swizzler_.reset(new ScopedClassSwizzler(
-        [NSEvent class],
-        [TestWindowDonor class],
-        @selector(window)));
+    swizzler_.reset(new base::mac::ScopedObjCClassSwizzler(
+        [NSEvent class], [TestWindowDonor class], @selector(window)));
   }
 
   void ClearSwizzle() {
     swizzler_.reset();
     g_test_window = nil;
   }
 
   NSEvent* TestMouseEvent(NSEventType type,
                           const gfx::Point &window_location,
                           NSInteger modifier_flags) {
@@ skipping 26 matching lines @@
         NSPointFromCGPoint(Flip(window_location).ToCGPoint());
     NSPoint screen_point = [test_window() convertBaseToScreen:window_point];
     CGFloat primary_screen_height =
         NSHeight([[[NSScreen screens] objectAtIndex:0] frame]);
     screen_point.y = primary_screen_height - screen_point.y;
     CGEventSetLocation(scroll, NSPointToCGPoint(screen_point));
     return [NSEvent eventWithCGEvent:scroll];
   }
 
  private:
-  scoped_ptr<ScopedClassSwizzler> swizzler_;
+  scoped_ptr<base::mac::ScopedObjCClassSwizzler> swizzler_;
 
   DISALLOW_COPY_AND_ASSIGN(EventsMacTest);
 };
 
 }  // namespace
 
 TEST_F(EventsMacTest, EventFlagsFromNative) {
   // Left click.
   NSEvent* left = cocoa_test_event_utils::MouseEventWithType(NSLeftMouseUp, 0);
   EXPECT_EQ(EF_LEFT_MOUSE_BUTTON, EventFlagsFromNative(left));
@@ skipping 175 matching lines @@
   event = cocoa_test_event_utils::MouseEventWithType(NSMouseMoved, 0);
   EXPECT_EQ(ui::ET_MOUSE_MOVED, ui::EventTypeFromNative(event));
 
   event = cocoa_test_event_utils::EnterExitEventWithType(NSMouseEntered);
   EXPECT_EQ(ui::ET_MOUSE_ENTERED, ui::EventTypeFromNative(event));
   event = cocoa_test_event_utils::EnterExitEventWithType(NSMouseExited);
   EXPECT_EQ(ui::ET_MOUSE_EXITED, ui::EventTypeFromNative(event));
 }
 
 }  // namespace ui