Adding the Copresence RpcHandler and HttpPost helper.

components/copresence/public/copresence_client.h

Index: components/copresence/public/copresence_client.h
diff --git a/components/copresence/public/copresence_client.h b/components/copresence/public/copresence_client.h
index 40b8bf97bfe4720e83416fae7eabd5e89574a568..219a0ebc835be454a4f22e00d06633c6cd420d7d 100644
--- a/components/copresence/public/copresence_client.h
+++ b/components/copresence/public/copresence_client.h
@@ -36,9 +36,9 @@ struct PendingRequest {
 };
 
 // The CopresenceClient class is the central interface for Copresence

[blundell, 2014/08/11 12:42:54]

The "Client" suffix is typically used in Chromium to indicate an interface
that's implemented and injected by the embedder (e.g., ContentClient,
AutofillClient, ...). AFAICT, that's not what this class is, but rather it's the
chief entrypoint to the component?

-// functionality. This class handles all the initialization and delegation of
-// copresence tasks. Any user of copresence only needs to interact with this
-// client.
+// functionality. This class handles all the initialization and delegation
+// of copresence tasks. Any user of copresence only needs to interact
+// with this client.
 class CopresenceClient : public base::SupportsWeakPtr<CopresenceClient> {
  public:
   // The delegate must outlive us.
@@ -54,9 +54,6 @@ class CopresenceClient : public base::SupportsWeakPtr<CopresenceClient> {
                             const std::string& app_id,
                             const StatusCallback& callback);
 
-  // Called before the API (and thus the Client) is destructed.
-  void Shutdown();
-
  private:
   void CompleteInitialization();
   void InitStepComplete(const std::string& step, bool success);