Fix includes of SkColorSpace

Required to land https://skia-review.googlesource.com/c/skia/+/526416

Change-Id: I7959b36c533f99334096a2bc467853a5aad92978
Bug: skia:13052
diff --git a/libs/hwui/tests/unit/SkiaCanvasTests.cpp b/libs/hwui/tests/unit/SkiaCanvasTests.cpp
index dae3c94..50d9f56 100644
--- a/libs/hwui/tests/unit/SkiaCanvasTests.cpp
+++ b/libs/hwui/tests/unit/SkiaCanvasTests.cpp
@@ -18,6 +18,7 @@
 
 #include <hwui/Paint.h>
 #include <SkCanvasStateUtils.h>
+#include <SkColorSpace.h>
 #include <SkPicture.h>
 #include <SkPictureRecorder.h>
 #include <gtest/gtest.h>