Move existing Mojo JS <--> CPP tests out of webui test harness.

mojo/public/interfaces/bindings/tests/js_to_cpp.mojom

-module mojo {

[sky, 2014/05/01 03:20:38]

I think this would better fit right next to the test rather than here.

[Tom Sepez, 2014/05/01 17:48:26]

I'm confused. Are you talking about the module statement or the comment that
follows?  Where did you intend it to go?  

+module js_to_cpp {
 
 // This struct encompasses all of the basic types, so that they
 // may be sent from C++ to JS and back for validation.
 struct EchoArgs {
   int64 si64;
   int32 si32;
   int16 si16;
   int8  si8;
   uint64 ui64;
   uint32 ui32;
   uint16 ui16;
   uint8  ui8;
   float float_val;
   float float_inf;
   float float_nan;
   double double_val;
   double double_inf;
   double double_nan;
   string name;
   string[] string_array;
 };
 
-[Peer=RendererTarget]
-interface BrowserTarget {
+[Peer=JsSide]
+interface CppSide {
+  StartTest();  // Sent to notify that the JS side is now ready.
   PingResponse();
   EchoResponse(EchoArgs arg1, EchoArgs arg2);
 };
 
-[Peer=BrowserTarget]
-interface RendererTarget {
+[Peer=CppSide]
+interface JsSide {
   Ping();
   Echo(EchoArgs arg);
 };
 
 }