Remove `Runnable` concept from base/bind_internal.h

base/bind_unittest.nc

Index: base/bind_unittest.nc
diff --git a/base/bind_unittest.nc b/base/bind_unittest.nc
index 70743f9177943b7f083abf61b122a2b6881981ed..bdbcd2f22378587b5a404967893f152c43c9abda 100644
--- a/base/bind_unittest.nc
+++ b/base/bind_unittest.nc
@@ -157,7 +157,7 @@ void WontCompile() {
   ref_cb.Run();
 }
 
-#elif defined(NCTEST_NO_IMPLICIT_ARRAY_PTR_CONVERSION)  // [r"fatal error: static_assert failed \"first bound argument to method cannot be array\""]
+#elif defined(NCTEST_NO_IMPLICIT_ARRAY_PTR_CONVERSION)  // [r"fatal error: static_assert failed \"First bound argument to a method cannot be an array.\""]
 
 // A method should not be bindable with an array of objects.
 //
@@ -171,7 +171,7 @@ void WontCompile() {
   method_bound_to_array_cb.Run();
 }
 
-#elif defined(NCTEST_NO_RAW_PTR_FOR_REFCOUNTED_TYPES)  // [r"fatal error: static_assert failed \"a parameter is a refcounted type and needs scoped_refptr\""]
+#elif defined(NCTEST_NO_RAW_PTR_FOR_REFCOUNTED_TYPES)  // [r"fatal error: static_assert failed \"A parameter is a refcounted type and needs scoped_refptr.\""]
 
 // Refcounted types should not be bound as a raw pointer.
 void WontCompile() {