Outline SkImageFilter Make methods

include/effects/SkImageSource.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageSource_DEFINED
 #define SkImageSource_DEFINED
 
 #include "SkImage.h"
 #include "SkImageFilter.h"
 
 class SK_API SkImageSource : public SkImageFilter {
 public:
-    static sk_sp<SkImageFilter> Make(sk_sp<SkImage> image) {
-        if (!image) {
-            return nullptr;
-        }
-
-        return sk_sp<SkImageFilter>(new SkImageSource(std::move(image)));
-    }
+    static sk_sp<SkImageFilter> Make(sk_sp<SkImage> image);
     static sk_sp<SkImageFilter> Make(sk_sp<SkImage> image,
                                      const SkRect& srcRect,
                                      const SkRect& dstRect,
-                                     SkFilterQuality filterQuality) {
-        if (!image) {
-            return nullptr;
-        }
-
-        return sk_sp<SkImageFilter>(new SkImageSource(std::move(image),
-                                                      srcRect, dstRect,
-                                                      filterQuality));
-    }
+                                     SkFilterQuality filterQuality);
 
     SkRect computeFastBounds(const SkRect& src) const override;
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkImageSource)
 
 #ifdef SK_SUPPORT_LEGACY_IMAGEFILTER_PTR
     static SkImageFilter* Create(SkImage* image) {
         return Make(sk_ref_sp<SkImage>(image)).release();
     }
@@ skipping 19 matching lines @@
                   SkFilterQuality);
 
     sk_sp<SkImage>   fImage;
     SkRect           fSrcRect, fDstRect;
     SkFilterQuality  fFilterQuality;
 
     typedef SkImageFilter INHERITED;
 };
 
 #endif