Reworks Channel pausing behavior

ipc/ipc_channel_proxy.h

Index: ipc/ipc_channel_proxy.h
diff --git a/ipc/ipc_channel_proxy.h b/ipc/ipc_channel_proxy.h
index b544a194ce1065a70af047eaf22dedab0850416a..06b3267117324006a1795bbf52cb4d7ec7e672c9 100644
--- a/ipc/ipc_channel_proxy.h
+++ b/ipc/ipc_channel_proxy.h
@@ -113,20 +113,21 @@ class IPC_EXPORT ChannelProxy : public Endpoint, public base::NonThreadSafe {
   // Initializes the channel proxy. Only call this once to initialize a channel
   // proxy that was not initialized in its constructor. If |create_pipe_now| is
   // true, the pipe is created synchronously. Otherwise it's created on the IO
-  // thread. If |create_paused| is true, outgoing messages will continue to be
-  // queued until Unpause() is called.
+  // thread.
   void Init(const IPC::ChannelHandle& channel_handle,
             Channel::Mode mode,
-            bool create_pipe_now,
-            bool create_paused = false);
+            bool create_pipe_now);
   void Init(std::unique_ptr<ChannelFactory> factory,
-            bool create_pipe_now,
-            bool create_paused = false);
+            bool create_pipe_now);
 
-  // Unpause the channel. Only useful if Init was called with |create_paused|.
-  // If |flush| is true the channel will be flushed as soon as it's unpaused.
-  // Otherwise you must explicitly call Flush() to flush messages which were
-  // queued while the channel was paused.
+  // Pause the channel. Subsequent calls to Send() will be internally queued
+  // until Unpause() is called. Queued messages will not be sent until the
+  // channel is flushed.
+  void Pause();
+
+  // Unpause the channel. If |flush| is true the channel will be flushed as soon
+  // as it's unpaused (see Flush() below.) Otherwise you must explicitly call
+  // Flush() to flush messages which were queued while the channel was paused.
   void Unpause(bool flush);
 
   // Flush the channel. This sends any messages which were queued before calling
@@ -288,11 +289,12 @@ class IPC_EXPORT ChannelProxy : public Endpoint, public base::NonThreadSafe {
     // Returns true if the message was processed, false otherwise.
     bool TryFilters(const Message& message);
 
+    void PauseChannel();
     void UnpauseChannel(bool flush);
     void FlushChannel();
 
     // Like Open and Close, but called on the IPC thread.
-    virtual void OnChannelOpened(bool pause);
+    virtual void OnChannelOpened();
     virtual void OnChannelClosed();
 
     // Called on the consumers thread when the ChannelProxy is closed.  At that