Implement improvements for request handling (issue #1327).

- Add a new CefRequestHandler::OnResourceResponse() method for inspecting the request/response headers and potentially restarting or redirecting the request.
- Add a new CefRequest::GetIdentifier() method for tracking a request across multiple CefRequestHandler callbacks.
- Pass a CefRequest object instead of just the old URL to CefRequestHandler::OnResourceRedirect().

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@2073 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

include/capi/cef_request_capi.h

@@ -159,6 +159,13 @@ typedef struct _cef_request_t {
   ///
   cef_transition_type_t (CEF_CALLBACK *get_transition_type)(
       struct _cef_request_t* self);
+
+  ///
+  // Returns the globally unique identifier for this request or 0 if not
+  // specified. Can be used by cef_request_tHandler implementations in the
+  // browser process to track a single request across multiple callbacks.
+  ///
+  uint64 (CEF_CALLBACK *get_identifier)(struct _cef_request_t* self);
 } cef_request_t;