Add LargeIconCache and LargeIconServiceFactory for iOS.

skia/ext/skia_utils_ios.mm

Index: skia/ext/skia_utils_ios.mm
diff --git a/skia/ext/skia_utils_ios.mm b/skia/ext/skia_utils_ios.mm
index 5655d22a5627ef98a19b4d07739d2fa86447346d..ec76cd5c19c36ca22546716b0aa6beb1feb79abf 100644
--- a/skia/ext/skia_utils_ios.mm
+++ b/skia/ext/skia_utils_ios.mm
@@ -123,4 +123,11 @@ std::vector<SkBitmap> ImageDataToSkBitmaps(NSData* image_data) {
   return frames;
 }
 
+UIColor* UIColorFromSkColor(SkColor color) {
+  return [UIColor colorWithRed:SkColorGetR(color) / 255.0f
+                         green:SkColorGetG(color) / 255.0f
+                          blue:SkColorGetB(color) / 255.0f
+                         alpha:SkColorGetA(color) / 255.0f];
+}
+
 }  // namespace gfx