Follow macro invocations when checking if a violation happened in a .cc file.

tools/clang/plugins/tests/inline_ctor.txt

-In file included from inline_ctor.cpp:5:
+In file included from inline_ctor.cpp:7:
 ./inline_ctor.h:13:3: warning: [chromium-style] Complex constructor has an inlined body.
   InlineCtorsArentOKInHeader() {}
   ^
 ./inline_ctor.h:14:3: warning: [chromium-style] Complex destructor has an inline body.
   ~InlineCtorsArentOKInHeader() {}
   ^
-./inline_ctor.h:82:1: warning: [chromium-style] Complex class/struct needs an explicit out-of-line constructor.
+./inline_ctor.h:31:25: warning: [chromium-style] Complex constructor has an inlined body.
+INLINE_CTORS_IN_A_MACRO(InlineCtorsBehindAMacroArentOKInHeader);
+                        ^
+./inline_ctor.h:31:1: warning: [chromium-style] Complex destructor has an inline body.
+INLINE_CTORS_IN_A_MACRO(InlineCtorsBehindAMacroArentOKInHeader);
+^
+./inline_ctor.h:25:5: note: expanded from macro 'INLINE_CTORS_IN_A_MACRO'
+    ~CLASS_NAME() {}                        \
+    ^
+./inline_ctor.h:95:1: warning: [chromium-style] Complex class/struct needs an explicit out-of-line constructor.
 struct FourNonTrivialMembers {
 ^
-./inline_ctor.h:82:1: warning: [chromium-style] Complex class/struct needs an explicit out-of-line destructor.
-4 warnings generated.
+./inline_ctor.h:95:1: warning: [chromium-style] Complex class/struct needs an explicit out-of-line destructor.
+6 warnings generated.