Allow IDL schemas to have comments on callback functions

tools/json_schema_compiler/test/idl_basics.idl

Index: tools/json_schema_compiler/test/idl_basics.idl
diff --git a/tools/json_schema_compiler/test/idl_basics.idl b/tools/json_schema_compiler/test/idl_basics.idl
index eb4ec62ccc158b2845ce8b869d82c364c6719048..647b0f1d46451a2383cb1363fce6ec5718ca5c88 100644
--- a/tools/json_schema_compiler/test/idl_basics.idl
+++ b/tools/json_schema_compiler/test/idl_basics.idl
@@ -26,6 +26,11 @@
   callback Callback3 = void(MyType1 arg);
   callback Callback4 = void(MyType2[] arg);
   callback Callback5 = void(EnumType type);
+  // A comment on a callback.
+  // |x|: A parameter.
+  callback Callback6 = void(long x);
+  // |x|: A parameter with no parent callback.

[asargent_no_longer_on_chrome, 2012/11/01 16:55:37]

nit: I don't quite understand the "with no parent callback" part of this
comment. Did you mean "with no parent comment"? (That's still confusing though,
because it looks like your function18 test below does use Callback7 both with
and without a parent comment.

[cduvall, 2012/11/01 22:56:01]

Done, should be more clear now.

+  callback Callback7 = void(long x);
 
   interface Functions {
     static void function1();
@@ -60,6 +65,11 @@
     // "switch" is a reserved word and should cause a C++ compile error if we
     // emit code for this declaration.
     [nocompile] static void function15(long switch);
+
+    static void function16(Callback6 cb);
+    static void function17(Callback7 cb);
+    // |cb|: Override callback comment.
+    static void function18(Callback7 cb);
   };
 
   interface Events {