Add SkImageFilter::makeColorSpace(SkColorSpaceXformer*)

Plus two sample implementations.  Will fill out the
rest if the model looks ok.

Bug: skia:
Change-Id: Ie24ecd0cbc36263220cb1e506f7812c582554e50
Reviewed-on: https://skia-review.googlesource.com/12100
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Matt Sarett <msarett@google.com>
diff --git a/src/core/SkColorSpaceXformer.cpp b/src/core/SkColorSpaceXformer.cpp
index 8a83dbc..d256ddf 100644
--- a/src/core/SkColorSpaceXformer.cpp
+++ b/src/core/SkColorSpaceXformer.cpp
@@ -11,6 +11,7 @@
 #include "SkDrawLooper.h"
 #include "SkGradientShader.h"
 #include "SkImage_Base.h"
+#include "SkImageFilter.h"
 #include "SkImagePriv.h"
 #include "SkMakeUnique.h"
 
@@ -172,8 +173,10 @@
         get_dst()->setDrawLooper(looper->makeColorSpace(this));
     }
 
-    // TODO:
-    //    - image filters?
+    if (auto imageFilter = src.getImageFilter()) {
+        get_dst()->setImageFilter(imageFilter->makeColorSpace(this));
+    }
+
     return *result;
 }