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

ui/base/clipboard/clipboard_mac.mm

Index: ui/base/clipboard/clipboard_mac.mm
diff --git a/ui/base/clipboard/clipboard_mac.mm b/ui/base/clipboard/clipboard_mac.mm
index 202a7f9ba948a86b2dede34128ac05ce8f37ae86..b97baa16b3491052e2590d4a3ae9c4088f19d19f 100644
--- a/ui/base/clipboard/clipboard_mac.mm
+++ b/ui/base/clipboard/clipboard_mac.mm
@@ -324,12 +324,17 @@ SkBitmap ClipboardMac::ReadImage(ClipboardType type, NSPasteboard* pb) const {
   } @catch (id exception) {
   }
 
-  SkBitmap bitmap;
   if (image.get()) {
-    bitmap = skia::NSImageToSkBitmapWithColorSpace(
-        image.get(), /*is_opaque=*/ false, base::mac::GetSystemColorSpace());
+    if ([[image representations] count] == 1u) {
+      NSBitmapImageRep* rep = [[image representations] objectAtIndex:0];

[Avi (use Gerrit), 2016/08/25 18:57:25]

NSImageRep* rep =
not
NSBitmapImageRep* rep =

You don't know what type of rep it is, and it doesn't matter for this call.

[erikchen, 2016/08/26 17:55:33]

Done.

+      return skia::NSImageRepToSkBitmapWithColorSpace(
+          rep, NSMakeSize([rep pixelsWide], [rep pixelsHigh]),
+          /*is_opaque=*/false, base::mac::GetSystemColorSpace());
+    }
+    return skia::NSImageToSkBitmapWithColorSpace(
+        image.get(), /*is_opaque=*/false, base::mac::GetSystemColorSpace());
   }
-  return bitmap;
+  return SkBitmap();
 }
 
 SkBitmap ClipboardMac::ReadImage(ClipboardType type) const {