mac: Don't lose pixels when copying a retina image from the clipboard.

ui/base/clipboard/clipboard_mac_unittest.mm

Index: ui/base/clipboard/clipboard_mac_unittest.mm
diff --git a/ui/base/clipboard/clipboard_mac_unittest.mm b/ui/base/clipboard/clipboard_mac_unittest.mm
index 3f5e336f04f925587f9655d8e6973fe9d0406a97..6a5577cf50365f974572da99045b69a3a0d8417e 100644
--- a/ui/base/clipboard/clipboard_mac_unittest.mm
+++ b/ui/base/clipboard/clipboard_mac_unittest.mm
@@ -58,8 +58,8 @@ TEST_F(ClipboardMacTest, ReadImageRetina) {
 
   SkBitmap bitmap = clipboard_mac->ReadImage(ui::CLIPBOARD_TYPE_COPY_PASTE,
                                              pasteboard->get());
-  EXPECT_EQ(width, bitmap.width());
-  EXPECT_EQ(height, bitmap.height());
+  EXPECT_EQ(2 * width, bitmap.width());
+  EXPECT_EQ(2 * height, bitmap.height());
 }
 
 TEST_F(ClipboardMacTest, ReadImageNonRetina) {