Switch to static_assert in base/.

base/observer_list_threadsafe.h

Index: base/observer_list_threadsafe.h
diff --git a/base/observer_list_threadsafe.h b/base/observer_list_threadsafe.h
index b9b4a624ca815da9efdf4d72423516b03f4637b6..e4204941949ff5996383b9906d916eca1322e85d 100644
--- a/base/observer_list_threadsafe.h
+++ b/base/observer_list_threadsafe.h
@@ -67,9 +67,8 @@ template <class T, class Method, class Params>
 class UnboundMethod {
  public:
   UnboundMethod(Method m, const Params& p) : m_(m), p_(p) {
-    COMPILE_ASSERT(
-        (internal::ParamsUseScopedRefptrCorrectly<Params>::value),
-        badunboundmethodparams);
+    static_assert((internal::ParamsUseScopedRefptrCorrectly<Params>::value),
+                  "bad unbound method params");
   }
   void Run(T* obj) const {
     DispatchToMethod(obj, m_, p_);