make pixelsnap textblob* etc gm portable

TBR=reed@google.com

Review URL: https://codereview.chromium.org/1263553002
diff --git a/gm/multipicturedraw.cpp b/gm/multipicturedraw.cpp
index 0e11b06..21c9d18 100644
--- a/gm/multipicturedraw.cpp
+++ b/gm/multipicturedraw.cpp
@@ -98,7 +98,7 @@
 
     SkPaint greyFill;
     greyFill.setStyle(SkPaint::kFill_Style);
-    greyFill.setColor(SK_ColorLTGRAY);
+    greyFill.setColor(sk_tool_utils::color_to_565(SK_ColorLTGRAY));
 
     SkPaint stroke;
     stroke.setStyle(SkPaint::kStroke_Style);
@@ -154,7 +154,7 @@
 
     SkPaint fill;
     fill.setStyle(SkPaint::kFill_Style);
-    fill.setColor(SK_ColorLTGRAY);
+    fill.setColor(sk_tool_utils::color_to_565(SK_ColorLTGRAY));
 
     SkPaint stroke;
     stroke.setStyle(SkPaint::kStroke_Style);
@@ -488,7 +488,7 @@
 
         void onOnceBeforeDraw() override {
             fPictures[0] = make_hex_plane_picture(SK_ColorWHITE);
-            fPictures[1] = make_hex_plane_picture(SK_ColorGRAY);
+            fPictures[1] = make_hex_plane_picture(sk_tool_utils::color_to_565(SK_ColorGRAY));
             fPictures[2] = make_sierpinski_picture();
             fPictures[3] = make_single_layer_hex_plane_picture();
         }