Mojo: Report bindings validation errors via MojoNotifyBadMessage

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

Index: mojo/public/cpp/bindings/lib/interface_endpoint_client.h
diff --git a/mojo/public/cpp/bindings/lib/interface_endpoint_client.h b/mojo/public/cpp/bindings/lib/interface_endpoint_client.h
index 3f820db3c30c66b179e6b2203478f66bb0b19509..abf801312a0ac68882178d2a960d7f4c580bfbb7 100644
--- a/mojo/public/cpp/bindings/lib/interface_endpoint_client.h
+++ b/mojo/public/cpp/bindings/lib/interface_endpoint_client.h
@@ -17,6 +17,7 @@
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_checker.h"
 #include "mojo/public/cpp/bindings/callback.h"
+#include "mojo/public/cpp/bindings/error.h"
 #include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/bindings/message_filter.h"
 #include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"
@@ -67,23 +68,30 @@ class InterfaceEndpointClient : public MessageReceiverWithResponder {
   AssociatedGroup* associated_group();
   uint32_t interface_id() const;
 
+  void set_interface_name(const std::string& name) {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    interface_name_ = name;
+  }
+
   // After this call the object is in an invalid state and shouldn't be reused.
   ScopedInterfaceEndpointHandle PassHandle();
 
   // Raises an error on the underlying message pipe. It disconnects the pipe
   // and notifies all interfaces running on this pipe.
-  void RaiseError();
+  void RaiseError(Error error);
 
   // MessageReceiverWithResponder implementation:
-  bool Accept(Message* message) override;
+  bool Accept(Message* message, Error* error) override;
   bool AcceptWithResponder(Message* message,
-                           MessageReceiver* responder) override;
+                           MessageReceiver* responder,
+                           Error* error) override;
 
   // The following methods are called by the router. They must be called
-  // outside of the router's lock.
+  // outside of the router's lock. If this returns false, |*error| contains more
+  // information about the failure reason.
 
   // NOTE: |message| must have passed message header validation.
-  bool HandleIncomingMessage(Message* message);
+  bool HandleIncomingMessage(Message* message, Error* error);
   void NotifyError();
 
  private:
@@ -116,7 +124,7 @@ class InterfaceEndpointClient : public MessageReceiverWithResponder {
     ~HandleIncomingMessageThunk() override;
 
     // MessageReceiver implementation:
-    bool Accept(Message* message) override;
+    bool Accept(Message* message, Error* error) override;
 
    private:
     InterfaceEndpointClient* const owner_;
@@ -124,7 +132,7 @@ class InterfaceEndpointClient : public MessageReceiverWithResponder {
     DISALLOW_COPY_AND_ASSIGN(HandleIncomingMessageThunk);
   };
 
-  bool HandleValidatedMessage(Message* message);
+  bool HandleValidatedMessage(Message* message, Error* error);
 
   ScopedInterfaceEndpointHandle handle_;
   std::unique_ptr<AssociatedGroup> associated_group_;
@@ -142,6 +150,10 @@ class InterfaceEndpointClient : public MessageReceiverWithResponder {
   Closure error_handler_;
   bool encountered_error_;
 
+  // The name of the interface which is bound by this client. Used only for
+  // debugging purposes.
+  std::string interface_name_;
+
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   base::ThreadChecker thread_checker_;