Add use-chromium-style-naming option to Blink GC plugin.

tools/clang/blink_gc_plugin/tests/trace_after_dispatch.txt

Index: tools/clang/blink_gc_plugin/tests/trace_after_dispatch.txt
diff --git a/tools/clang/blink_gc_plugin/tests/trace_after_dispatch.txt b/tools/clang/blink_gc_plugin/tests/trace_after_dispatch.txt
index 877fbbe6fdd166855ea3d5ad9e639456c1ab3cdb..48739991c75e9fdcd6b91a4af28580d5452e7314 100644
--- a/tools/clang/blink_gc_plugin/tests/trace_after_dispatch.txt
+++ b/tools/clang/blink_gc_plugin/tests/trace_after_dispatch.txt
@@ -1,11 +1,11 @@
 trace_after_dispatch.cpp:11:1: warning: [blink-gc] Missing dispatch to class 'D' in manual trace dispatch.
-void A::trace(Visitor* visitor)
+void A::Trace(Visitor* visitor)
 ^
 trace_after_dispatch.cpp:30:1: warning: [blink-gc] Base class 'A' of derived class 'B' requires tracing.
-void B::traceAfterDispatch(Visitor* visitor)
+void B::TraceAfterDispatch(Visitor* visitor)
 ^
 trace_after_dispatch.cpp:38:1: warning: [blink-gc] Class 'C' has untraced fields that require tracing.
-void C::traceAfterDispatch(Visitor* visitor)
+void C::TraceAfterDispatch(Visitor* visitor)
 ^
 ./trace_after_dispatch.h:36:5: note: [blink-gc] Untraced field 'm_a' declared here:
     Member<A> m_a;