Clean up a few includes, introduce iwyu.

src/ports/SkMemory_malloc.cpp

-
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
 #include "SkTypes.h"
-#include <stdio.h>
+
 #include <stdlib.h>
 
 #define SK_DEBUGFAILF(fmt, ...) \
     SkASSERT((SkDebugf(fmt"\n", __VA_ARGS__), false))
 
 static inline void sk_out_of_memory(size_t size) {
     SK_DEBUGFAILF("sk_out_of_memory (asked for " SK_SIZE_T_SPECIFIER " bytes)",
                   size);
     abort();
 }
@@ skipping 39 matching lines @@
     }
 }
 
 void* sk_calloc(size_t size) {
     return calloc(size, 1);
 }
 
 void* sk_calloc_throw(size_t size) {
     return throw_on_failure(size, sk_calloc(size));
 }