Add FlushForTesting to InterfacePtr and Binding.

mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h

Index: mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
diff --git a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
index c7f74fbb9c370cc76ba0cc3ffe5d0688d9f8c35d..1cfc5d61986d5cbed70a9d6dc522ff5b9d4eb96e 100644
--- a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
+++ b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
@@ -22,6 +22,7 @@
 #include "mojo/public/cpp/bindings/associated_interface_ptr_info.h"
 #include "mojo/public/cpp/bindings/interface_endpoint_client.h"
 #include "mojo/public/cpp/bindings/interface_id.h"
+#include "mojo/public/cpp/bindings/lib/control_message_handler.h"
 #include "mojo/public/cpp/bindings/lib/control_message_proxy.h"
 #include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"
 #include "mojo/public/cpp/system/message_pipe.h"
@@ -52,12 +53,11 @@ class AssociatedInterfacePtrState {
   }
 
   void QueryVersion(const base::Callback<void(uint32_t)>& callback) {
-    // Do a static cast in case the interface contains methods with the same
-    // name. It is safe to capture |this| because the callback won't be run
-    // after this object goes away.
-    static_cast<ControlMessageProxy*>(proxy_.get())
-        ->QueryVersion(base::Bind(&AssociatedInterfacePtrState::OnQueryVersion,
-                                  base::Unretained(this), callback));
+    // It is safe to capture |this| because the callback won't be run after this
+    // object goes away.
+    endpoint_client_->control_message_proxy()->QueryVersion(
+        base::Bind(&AssociatedInterfacePtrState::OnQueryVersion,
+                   base::Unretained(this), callback));
   }
 
   void RequireVersion(uint32_t version) {
@@ -65,9 +65,14 @@ class AssociatedInterfacePtrState {
       return;
 
     version_ = version;
-    // Do a static cast in case the interface contains methods with the same
-    // name.
-    static_cast<ControlMessageProxy*>(proxy_.get())->RequireVersion(version);
+    endpoint_client_->control_message_proxy()->RequireVersion(version);
+  }
+
+  void FlushForTesting() {
+    if (encountered_error() || !proxy_)

[yzshen1, 2016/08/29 23:24:58]

Does it make sense to remove this check? (Currently it is done at multiple
places.)

If |endpoint_client_| is null, then it is the user's responsibility to avoid
calling this method, just like RequireVersion above.

And we can let control_message_proxy() itself checks whether error has been
encountered.

[Sam McNally, 2016/08/30 03:05:51]

Done.

+      return;
+
+    endpoint_client_->control_message_proxy()->FlushForTesting();
   }
 
   void Swap(AssociatedInterfacePtrState* other) {
@@ -88,7 +93,7 @@ class AssociatedInterfacePtrState {
     endpoint_client_.reset(new InterfaceEndpointClient(
         info.PassHandle(), nullptr,
         base::WrapUnique(new typename Interface::ResponseValidator_()), false,
-        std::move(runner)));
+        std::move(runner), 0u));

[yzshen1, 2016/08/29 23:24:58]

Please comment on why we use 0 here. It might not be obvious to the readers.

[Sam McNally, 2016/08/30 03:05:51]

Done.

     proxy_.reset(new Proxy(endpoint_client_.get()));
     proxy_->serialization_context()->group_controller =
         endpoint_client_->group_controller();
@@ -132,6 +137,10 @@ class AssociatedInterfacePtrState {
     callback.Run(version);
   }
 
+  void OnConnectionError() {

[yzshen1, 2016/08/29 23:24:58]

I think this is not used.

[Sam McNally, 2016/08/30 03:05:51]

Done.

+    endpoint_client_->control_message_proxy()->OnConnectionError();
+  }
+
   std::unique_ptr<InterfaceEndpointClient> endpoint_client_;
   std::unique_ptr<Proxy> proxy_;