Revert of IWYU: 'core' target, files starting A-C.

src/core/SkColorFilter.cpp

Index: src/core/SkColorFilter.cpp
diff --git a/src/core/SkColorFilter.cpp b/src/core/SkColorFilter.cpp
index 9cbcc6401798feebe4e5967890ad44af08187399..8e01090dd324f713a7bdd4dd8f0b34122c4cba05 100644
--- a/src/core/SkColorFilter.cpp
+++ b/src/core/SkColorFilter.cpp
@@ -7,13 +7,8 @@
 
 #include "SkColorFilter.h"
 #include "SkReadBuffer.h"
-#include "SkRefCnt.h"
 #include "SkString.h"
-#include "SkTDArray.h"
-#include "SkUnPreMultiply.h"
 #include "SkWriteBuffer.h"
-
-class GrFragmentProcessor;
 
 bool SkColorFilter::asColorMode(SkColor* color, SkXfermode::Mode* mode) const {
     return false;