IWYU for some more test files starting with 'C'.

Change-Id: I010527b342cbfa0b425ef0d00966219413d9e77d
Reviewed-on: https://skia-review.googlesource.com/121886
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/tests/ColorFilterTest.cpp b/tests/ColorFilterTest.cpp
index dc4a3a0..669ced2 100644
--- a/tests/ColorFilterTest.cpp
+++ b/tests/ColorFilterTest.cpp
@@ -6,16 +6,18 @@
  */
 
 #include "SkAutoMalloc.h"
+#include "SkBlendMode.h"
 #include "SkColor.h"
 #include "SkColorFilter.h"
-#include "SkColorPriv.h"
-#include "SkLumaColorFilter.h"
 #include "SkRandom.h"
 #include "SkReadBuffer.h"
+#include "SkRefCnt.h"
 #include "SkWriteBuffer.h"
-#include "SkRandom.h"
+#include "SkTypes.h"
 #include "Test.h"
 
+class SkFlattenable;
+
 static sk_sp<SkColorFilter> reincarnate_colorfilter(SkFlattenable* obj) {
     SkBinaryWriteBuffer wb;
     wb.writeFlattenable(obj);