Correctly truncate in Windows eventhandler.

runtime/bin/eventhandler_win.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef BIN_EVENTHANDLER_WIN_H_
 #define BIN_EVENTHANDLER_WIN_H_
 
 #if !defined(BIN_EVENTHANDLER_H_)
 #error Do not include eventhandler_win.h directly; use eventhandler.h instead.
 #endif
@@ skipping 171 matching lines @@
       handle_->Unlock();
     }
 
    private:
     Handle* handle_;
   };
 
   virtual ~Handle();
 
   // Socket interface exposing normal socket operations.
-  int Available();
-  int Read(void* buffer, int num_bytes);
-  int RecvFrom(
-      void* buffer, int num_bytes, struct sockaddr* sa, socklen_t addr_len);
-  virtual int Write(const void* buffer, int num_bytes);
-  virtual int SendTo(const void* buffer,
-                     int num_bytes,
-                     struct sockaddr* sa,
-                     socklen_t sa_len);
+  intptr_t Available();
+  intptr_t Read(void* buffer, intptr_t num_bytes);
+  intptr_t RecvFrom(void* buffer,
+                    intptr_t num_bytes,
+                    struct sockaddr* sa,
+                    socklen_t addr_len);
+  virtual intptr_t Write(const void* buffer, intptr_t num_bytes);
+  virtual intptr_t SendTo(const void* buffer,
+                          intptr_t num_bytes,
+                          struct sockaddr* sa,
+                          socklen_t sa_len);
 
   // Internal interface used by the event handler.
   virtual bool IssueRead();
   virtual bool IssueRecvFrom();
   virtual bool IssueWrite();
   virtual bool IssueSendTo(struct sockaddr* sa, socklen_t sa_len);
   bool HasPendingRead();
   bool HasPendingWrite();
   void ReadComplete(OverlappedBuffer* buffer);
   void RecvFromComplete(OverlappedBuffer* buffer);
@@ skipping 106 matching lines @@
         write_thread_running_(false),
         write_monitor_(new Monitor()) {
     type_ = kStd;
   }
 
   ~StdHandle() {
     delete write_monitor_;
   }
 
   virtual void DoClose();
-  virtual int Write(const void* buffer, int num_bytes);
+  virtual intptr_t Write(const void* buffer, intptr_t num_bytes);
 
   void WriteSyncCompleteAsync();
   void RunWriteLoop();
 
  private:
   DWORD thread_wrote_;
   bool write_thread_exists_;
   bool write_thread_running_;
   dart::Monitor* write_monitor_;
 };
@@ skipping 201 matching lines @@
 
   TimeoutQueue timeout_queue_;  // Time for next timeout.
   bool shutdown_;
   HANDLE completion_port_;
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_EVENTHANDLER_WIN_H_