mac: Remove implicit conversion from ImageSkia to SkBitmap.

skia/ext/skia_utils_mac.mm

Index: skia/ext/skia_utils_mac.mm
diff --git a/skia/ext/skia_utils_mac.mm b/skia/ext/skia_utils_mac.mm
index ed41b60e5948b4f6d3bd76e1c0bc6eb38adc8bfb..b372adf38fa2fcfe1ebce463483bc5bf0ef33a33 100644
--- a/skia/ext/skia_utils_mac.mm
+++ b/skia/ext/skia_utils_mac.mm
@@ -214,7 +214,12 @@ SkBitmap NSImageRepToSkBitmap(
 NSBitmapImageRep* SkBitmapToNSBitmapImageRep(const SkBitmap& skiaBitmap) {
   base::mac::ScopedCFTypeRef<CGColorSpaceRef> color_space(
       CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB));
+  return SkBitmapToNSBitmapImageRepWithColorSpace(skiaBitmap, color_space);
+}
 
+NSBitmapImageRep* SkBitmapToNSBitmapImageRepWithColorSpace(
+    const SkBitmap& image,
+    CGColorSpaceRef colorSpace) {
   // First convert SkBitmap to CGImageRef.
   base::mac::ScopedCFTypeRef<CGImageRef> cgimage(
       SkCreateCGImageRefWithColorspace(skiaBitmap, color_space));