Check alpha-sorting of includes during presubmit.

test/cctest/test-hashmap.cc

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 10 matching lines @@
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <stdlib.h>
 
 #include "src/v8.h"
+#include "test/cctest/cctest.h"
+
 #include "src/hashmap.h"
-#include "test/cctest/cctest.h"
 
 using namespace v8::internal;
 
 static bool DefaultMatchFun(void* a, void* b) {
   return a == b;
 }
 
 
 typedef uint32_t (*IntKeyHash)(uint32_t key);
 
@@ skipping 124 matching lines @@
     }
   }
   CHECK_EQ(0, set.occupancy());
 }
 
 
 TEST(Set) {
   TestSet(Hash, 100);
   TestSet(CollisionHash, 50);
 }