Fix ArcBridgeBootstrap race issues.

components/arc/arc_bridge_bootstrap.h

Index: components/arc/arc_bridge_bootstrap.h
diff --git a/components/arc/arc_bridge_bootstrap.h b/components/arc/arc_bridge_bootstrap.h
index 25a59f88dbfe29926e0c741787b1dbade6fb4921..8aef4cd01d94963b8410b7a0db3934d0a2388c06 100644
--- a/components/arc/arc_bridge_bootstrap.h
+++ b/components/arc/arc_bridge_bootstrap.h
@@ -18,15 +18,25 @@ namespace arc {
 // Starts the ARC instance and bootstraps the bridge connection.
 // Clients should implement the Delegate to be notified upon communications
 // being available.
+// The instance can be safely removed 1) before Start() is called, or 2) after
+// OnStopped() is called.
+// The number of instances must be at most one. Otherwise, ARC instances will
+// conflict.
+// TODO(hidehiko): This class manages more than "bootstrap" procedure now.
+// Rename this to ArcSession.
 class ArcBridgeBootstrap {
  public:
+  // TODO(hidehiko): Switch to Observer style, which fits more for this design.
   class Delegate {
    public:
     // Called when the connection with ARC instance has been established.
-    virtual void OnConnectionEstablished(
-        mojom::ArcBridgeInstancePtr instance_ptr) = 0;
+    // This can be called after Start() at most once.
+    // On error case, OnStopped() below is called, and OnReady() may not
+    // called.
+    virtual void OnReady() = 0;
 
-    // Called when ARC instance is stopped.
+    // Called when ARC instance is stopped. This is called exactly once
+    // per instance which is Start()ed.
     virtual void OnStopped(ArcBridgeService::StopReason reason) = 0;
   };
 
@@ -39,11 +49,13 @@ class ArcBridgeBootstrap {
   void set_delegate(Delegate* delegate) { delegate_ = delegate; }
 
   // Starts and bootstraps a connection with the instance. The Delegate's
-  // OnConnectionEstablished() will be called if the bootstrapping is
-  // successful, or OnStopped() if it is not.
+  // OnReady() will be called if the bootstrapping is successful, or
+  // OnStopped() if it is not.
+  // Start() cannot be called twice or more.

[Luis Héctor Chávez, 2016/08/01 17:47:38]

nit: s/cannot/should not/

[hidehiko, 2016/08/02 11:36:22]

Done.

   virtual void Start() = 0;
 
-  // Stops the currently-running instance.
+  // Requests to stop the currently-running instance.
+  // The completion is notified via OnStopped() of the Delegate.
   virtual void Stop() = 0;
 
  protected: