Cleanup: Sanitize the order of includes under tests/

Initially this was to make sure Test.h appeared after the Sk*.h includes.

Patch generated by the following command line:

$ ~/chromium/src/tools/sort-headers.py tests/*.cpp

BUG=None
TEST=tests
R=robertphillips@google.com

Review URL: https://codereview.chromium.org/145313004

git-svn-id: http://skia.googlecode.com/svn/trunk@13177 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/StringTest.cpp b/tests/StringTest.cpp
index a911a85..13ee5ec 100644
--- a/tests/StringTest.cpp
+++ b/tests/StringTest.cpp
@@ -5,10 +5,10 @@
  * found in the LICENSE file.
  */
 
-#include "Test.h"
-#include "SkString.h"
 #include <stdarg.h>
 #include <stdio.h>
+#include "SkString.h"
+#include "Test.h"
 
 // Windows vsnprintf doesn't 0-terminate safely), but is so far
 // encapsulated in SkString that we can't test it directly.