Add support for HTTP handlers that are in self-contained apps. Also add an example app.

services/http_server/public/http_server.mojom

Index: services/http_server/public/http_server.mojom
diff --git a/services/http_server/public/http_server.mojom b/services/http_server/public/http_server.mojom
index d5e982b89d90394be5cc79b69a0b07a3693d3c75..2fa327af242bc5874dff3d82f12e0380f02ac268 100644
--- a/services/http_server/public/http_server.mojom
+++ b/services/http_server/public/http_server.mojom
@@ -4,4 +4,22 @@
 
 module mojo;
 
-// TODO(jam): interface for http_server
+import "services/http_server/public/http_request.mojom";
+import "services/http_server/public/http_response.mojom";
+
+[Client=HttpServerClient]
+interface HttpServerService {
+  // Add a handler for the given regex path.
+  AddHandler(string path) => (bool success);
+
+  // Remove a previously registered handler.
+  RemoveHandler(string path) => (bool success);
+
+  // Helper method to create an HttpResponse given the status code and body.
+  CreateResponse(uint32 status_code, string body) => (HttpResponse response);

[yzshen1, 2014/11/12 17:38:34]

It seems this could be done in a client-side utility, instead of making a
round-trip to do it at the service side. WDYT?

[jam, 2014/11/12 20:48:40]

yeah that's better; done

+};
+
+[Client=HttpServerService]

[yzshen1, 2014/11/12 17:38:33]

Nit: usually you don't need to add this attribute, unless you want to explicitly
request/pass HttpServerClient interface in the mojom definition. (Typically you
only pass/request HttpServerService.)

[jam, 2014/11/12 20:48:41]

ah, I didn't know that, thanks. i had copied this from viewmanagerservice.
should that be changed as well?

[yzshen1, 2014/11/12 21:24:26]

IMO it is nice to change but not a big issue.

+interface HttpServerClient {
+  OnHandleRequest(HttpRequest request) => (HttpResponse response);
+};