Add reprioritization to socket pools.

net/socket/client_socket_pool_base.h

Index: net/socket/client_socket_pool_base.h
diff --git a/net/socket/client_socket_pool_base.h b/net/socket/client_socket_pool_base.h
index f221f8e330ca39fbf575832ae7a5f73d2d2794bf..2bcfdc8d9839c9ec4ba3cee928f1e350ca61c8aa 100644
--- a/net/socket/client_socket_pool_base.h
+++ b/net/socket/client_socket_pool_base.h
@@ -196,6 +196,7 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
     ClientSocketHandle* handle() const { return handle_; }
     const CompletionCallback& callback() const { return callback_; }
     RequestPriority priority() const { return priority_; }
+    void set_priority(RequestPriority priority) { priority_ = priority; }
     ClientSocketPool::RespectLimits respect_limits() const {
       return respect_limits_;
     }
@@ -214,8 +215,7 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
 
     ClientSocketHandle* const handle_;
     const CompletionCallback callback_;
-    // TODO(akalin): Support reprioritization.
-    const RequestPriority priority_;
+    RequestPriority priority_;
     const ClientSocketPool::RespectLimits respect_limits_;
     const Flags flags_;
     const NetLogWithSource net_log_;
@@ -266,13 +266,18 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
 
   // See ClientSocketPool::RequestSocket for documentation on this function.
   int RequestSocket(const std::string& group_name,
-                    std::unique_ptr<const Request> request);
+                    std::unique_ptr<Request> request);
 
-  // See ClientSocketPool::RequestSocket for documentation on this function.
+  // See ClientSocketPool::RequestSockets for documentation on this function.
   void RequestSockets(const std::string& group_name,
                       const Request& request,
                       int num_sockets);
 
+  // See ClientSocketPool::SetPriority for documentation on this function.
+  void SetPriority(const std::string& group_name,
+                   ClientSocketHandle* handle,
+                   RequestPriority priority);
+
   // See ClientSocketPool::CancelRequest for documentation on this function.
   void CancelRequest(const std::string& group_name,
                      ClientSocketHandle* handle);
@@ -380,8 +385,8 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
     base::TimeTicks start_time;
   };
 
-  typedef PriorityQueue<const Request*> RequestQueue;
-  typedef std::map<const ClientSocketHandle*, const Request*> RequestMap;
+  typedef PriorityQueue<Request*> RequestQueue;
+  typedef std::map<const ClientSocketHandle*, Request*> RequestMap;
 
   // A Group is allocated per group_name when there are idle sockets or pending
   // requests.  Otherwise, the Group object is removed from the map.
@@ -459,17 +464,22 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
     // Inserts the request into the queue based on priority
     // order. Older requests are prioritized over requests of equal
     // priority.
-    void InsertPendingRequest(std::unique_ptr<const Request> request);
+    void InsertPendingRequest(std::unique_ptr<Request> request);
 
     // Gets and removes the next pending request. Returns NULL if
     // there are no pending requests.
-    std::unique_ptr<const Request> PopNextPendingRequest();
+    std::unique_ptr<Request> PopNextPendingRequest();
 
     // Finds the pending request for |handle| and removes it. Returns
     // the removed pending request, or NULL if there was none.
-    std::unique_ptr<const Request> FindAndRemovePendingRequest(
+    std::unique_ptr<Request> FindAndRemovePendingRequest(
         ClientSocketHandle* handle);
 
+    // Change the priority of the request named by |*handle|.  |*handle|
+    // must refer to a request currently present in the group.  If |priority|
+    // is the same as the current priority of the request, this is a no-op.
+    void SetPriority(ClientSocketHandle* handle, RequestPriority priority);
+
     void IncrementActiveSocketCount() { active_socket_count_++; }
     void DecrementActiveSocketCount() { active_socket_count_--; }
 
@@ -482,7 +492,7 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
    private:
     // Returns the iterator's pending request after removing it from
     // the queue.
-    std::unique_ptr<const Request> RemovePendingRequest(
+    std::unique_ptr<Request> RemovePendingRequest(
         const RequestQueue::Pointer& pointer);
 
     // Called when the backup socket timer fires.
@@ -753,7 +763,7 @@ class ClientSocketPoolBase {
                     ClientSocketHandle* handle,
                     const CompletionCallback& callback,
                     const NetLogWithSource& net_log) {
-    std::unique_ptr<const Request> request(new Request(
+    std::unique_ptr<Request> request(new Request(
         handle, callback, priority, respect_limits,
         internal::ClientSocketPoolBaseHelper::NORMAL, params, net_log));
     return helper_.RequestSocket(group_name, std::move(request));
@@ -773,6 +783,12 @@ class ClientSocketPoolBase {
     helper_.RequestSockets(group_name, request, num_sockets);
   }
 
+  void SetPriority(const std::string& group_name,
+                   ClientSocketHandle* handle,
+                   RequestPriority priority) {
+    return helper_.SetPriority(group_name, handle, priority);
+  }
+
   void CancelRequest(const std::string& group_name,
                      ClientSocketHandle* handle) {
     return helper_.CancelRequest(group_name, handle);