Revert of Implement THROTTLED priority semantics.

net/base/network_throttle_manager.h

Index: net/base/network_throttle_manager.h
diff --git a/net/base/network_throttle_manager.h b/net/base/network_throttle_manager.h
index 96a864e678488ab807635abc54a495b57875b3e8..4fde0f245d249efcd1820247b54dfaf7d1d78e27 100644
--- a/net/base/network_throttle_manager.h
+++ b/net/base/network_throttle_manager.h
@@ -24,13 +24,12 @@
 // Methods are virtual to allow for test mocks.
 class NET_EXPORT_PRIVATE NetworkThrottleManager {
  public:
-  class Throttle;
-
   // Abstract base class other classes can inherit from to get
   // notifications from throttle state changes.
   class NET_EXPORT_PRIVATE ThrottleDelegate {
    public:
-    // Called when a throttle is unblocked.
+    // Called whenever the throttle state of this stream has changed.
+    // The new state can be determined through Throttle::IsThrottled().
     //
     // Note that this call may occur as the result of either a call to
     // Throttle::SetPriority (on the throttle related to this delegate
@@ -38,7 +37,7 @@
     // so will occur synchronously during those events.  It will not
     // be called from the destructor of the Throttle associated with
     // the ThrottleDelegate.
-    virtual void OnThrottleUnblocked(Throttle* throttle) = 0;
+    virtual void OnThrottleStateChanged() = 0;
 
    protected:
     virtual ~ThrottleDelegate() {}
@@ -46,28 +45,24 @@
 
   // Class owned by external stream representations that
   // routes notifications.  It may be constructed in either the
-  // blocked or unblocked state according to the state of the
-  // NetworkThrottleManager; if it's constructed in the unblocked
-  // state, it will only make a single transition to unblocked,
-  // which will be signaled by delegate->OnThrottleUnblocked(this).
-  // If it's constructed in the unblocked state, it will remain
+  // throttled or unthrottled state according to the state of the
+  // NetworkThrottleManager; if it's constructed in the throttled
+  // state, it will only make a single transition to unthrottled,
+  // which will be signaled by delegate->OnThrottleStateChanged().
+  // If it's constructed in the unthrottled state, it will remain
   // there.
   class NET_EXPORT_PRIVATE Throttle {
    public:
     virtual ~Throttle() {}
 
-    virtual bool IsBlocked() const = 0;
-
-    virtual RequestPriority Priority() const = 0;
+    virtual bool IsThrottled() const = 0;
 
     // Note that this may result in a possibly reentrant call to
-    // |ThrottleDelegate::OnThrottleUnblocked|, as well as the resumption
+    // |ThrottleDelegate::OnThrottleStateChanged|, as well as the resumption
     // of this or other requests, which may result in request completion
     // and destruction before return.  Any caller of this function
     // should not rely on this object or containing objects surviving
     // this call.
-    //
-    // This call is a no-op if the priority is set to its current value.
     virtual void SetPriority(RequestPriority priority) = 0;
 
    protected:
@@ -85,6 +80,8 @@
                                                    RequestPriority priority,
                                                    bool ignore_limits) = 0;
 
+  static std::unique_ptr<NetworkThrottleManager> CreateThrottler();
+
  protected:
   NetworkThrottleManager() {}