Dont break between (( in __attribute__((.

Before:
void aaaaaaaaaaaaaaaaaa() __attribute__(
    (aaaaaaaaaaaaaaaaaaaaaaaaa, aaaaaaaaaaaaaaaaaaaaaaaaa,
     aaaaaaaaaaaaaaaaaaaaaaaaa));

After:
void aaaaaaaaaaaaaaaaaa()
    __attribute__((aaaaaaaaaaaaaaaaaaaaaaaaa, aaaaaaaaaaaaaaaaaaaaaaaaa,
                   aaaaaaaaaaaaaaaaaaaaaaaaa));

llvm-svn: 176260
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 02c7493..392548d 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -1334,6 +1334,10 @@
                "    GUARDED_BY(aaaaaaaaaaaaa);");
   verifyFormat("void aaaaaaaaaaaa(int aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) const\n"
                "    GUARDED_BY(aaaaaaaaaaaaa) {}");
+  verifyFormat(
+      "void aaaaaaaaaaaaaaaaaa()\n"
+      "    __attribute__((aaaaaaaaaaaaaaaaaaaaaaaaa, aaaaaaaaaaaaaaaaaaaaaaa,\n"
+      "                   aaaaaaaaaaaaaaaaaaaaaaaaa));");
 }
 
 TEST_F(FormatTest, BreaksAccordingToOperatorPrecedence) {