Implement throttling behavior for LocalStorage mojo messages.

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_INTERFACE_PTR_STATE_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_INTERFACE_PTR_STATE_H_
 
 #include <stdint.h>
 
 #include <algorithm>  // For |std::swap()|.
@@ skipping 131 matching lines @@
 
     DCHECK(endpoint_client_);
     endpoint_client_->set_connection_error_with_reason_handler(error_handler);
   }
 
   // Returns true if bound and awaiting a response to a message.
   bool has_pending_callbacks() const {
     return endpoint_client_ && endpoint_client_->has_pending_responders();
   }
 
+  size_t pending_callback_count() const {
+    return endpoint_client_ ? endpoint_client_->pending_responder_count() : 0;
+  }
+
   AssociatedGroup* associated_group() {
     ConfigureProxyIfNecessary();
     return endpoint_client_->associated_group();
   }
 
   void EnableTestingMode() {
     ConfigureProxyIfNecessary();
     router_->EnableTestingMode();
   }
 
   void ForwardMessage(Message message) {
     ConfigureProxyIfNecessary();
     endpoint_client_->Accept(&message);
   }
 
   void ForwardMessageWithResponder(Message message,
                                    std::unique_ptr<MessageReceiver> responder) {
     ConfigureProxyIfNecessary();
     endpoint_client_->AcceptWithResponder(&message, responder.release());
   }
 
+  void set_process_async_during_sync(bool value) {
+    DCHECK(!router_);
+    process_async_during_sync_ = value;
+  }
+
  private:
   using Proxy = typename Interface::Proxy_;
 
   void ConfigureProxyIfNecessary() {
     // The proxy has been configured.
     if (proxy_) {
       DCHECK(router_);
       DCHECK(endpoint_client_);
       return;
     }
     // The object hasn't been bound.
     if (!handle_.is_valid())
       return;
 
     MultiplexRouter::Config config =
         Interface::PassesAssociatedKinds_
             ? MultiplexRouter::MULTI_INTERFACE
             : (Interface::HasSyncMethods_
                    ? MultiplexRouter::SINGLE_INTERFACE_WITH_SYNC_METHODS
                    : MultiplexRouter::SINGLE_INTERFACE);
-    router_ = new MultiplexRouter(std::move(handle_), config, true, runner_);
+    router_ = new MultiplexRouter(
+        std::move(handle_), config, true, runner_,
+        process_async_during_sync_
+            ? MultiplexRouter::ALLOW_DIRECT_CLIENT_CALLS
+            : MultiplexRouter::ALLOW_DIRECT_CLIENT_CALLS_FOR_SYNC_MESSAGES);
     router_->SetMasterInterfaceName(Interface::Name_);
     endpoint_client_.reset(new InterfaceEndpointClient(
         router_->CreateLocalEndpointHandle(kMasterInterfaceId), nullptr,
         base::WrapUnique(new typename Interface::ResponseValidator_()), false,
         std::move(runner_),
         // The version is only queried from the client so the value passed here
         // will not be used.
         0u));
     proxy_.reset(new Proxy(endpoint_client_.get()));
     if (Interface::PassesAssociatedKinds_)
@@ skipping 12 matching lines @@
   std::unique_ptr<Proxy> proxy_;
 
   // |router_| (as well as other members above) is not initialized until
   // read/write with the message pipe handle is needed. |handle_| is valid
   // between the Bind() call and the initialization of |router_|.
   ScopedMessagePipeHandle handle_;
   scoped_refptr<base::SingleThreadTaskRunner> runner_;
 
   uint32_t version_;
 
+  bool process_async_during_sync_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(InterfacePtrState);
 };
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_INTERFACE_PTR_STATE_H_