Add support for writing ICC profiles in png encodes

BUG=skia:

Change-Id: I99eb2f157f249ed09d724461ec4a1e31db70816a
Reviewed-on: https://skia-review.googlesource.com/9782
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>
diff --git a/gm/encode-srgb.cpp b/gm/encode-srgb.cpp
index 991e6a1..2a89ea3 100644
--- a/gm/encode-srgb.cpp
+++ b/gm/encode-srgb.cpp
@@ -119,7 +119,7 @@
 
     SkEncodeOptions options;
     if (bitmap.colorSpace()) {
-        options.fPremulBehavior = SkEncodeOptions::PremulBehavior::kGammaCorrect;
+        options.fColorBehavior = SkEncodeOptions::ColorBehavior::kCorrect;
     }
 
     switch (format) {