Another round of cleanups for http://www.dartbug.com/15922

runtime/bin/file.cc

 // Copyright (c) 2013, 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.
 
 #include "bin/file.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/io_buffer.h"
 #include "bin/thread.h"
@@ skipping 13 matching lines @@
 static File* GetFilePointer(Dart_Handle handle) {
   intptr_t value = DartUtils::GetIntptrValue(handle);
   return reinterpret_cast<File*>(value);
 }
 
 
 bool File::ReadFully(void* buffer, int64_t num_bytes) {
   int64_t remaining = num_bytes;
   char* current_buffer = reinterpret_cast<char*>(buffer);
   while (remaining > 0) {
-    int bytes_read = Read(current_buffer, remaining);
+    int64_t bytes_read = Read(current_buffer, remaining);
     if (bytes_read <= 0) {
       return false;
     }
     remaining -= bytes_read;  // Reduce the number of remaining bytes.
     current_buffer += bytes_read;  // Move the buffer forward.
   }
   return true;
 }
 
 
 bool File::WriteFully(const void* buffer, int64_t num_bytes) {
   int64_t remaining = num_bytes;
   const char* current_buffer = reinterpret_cast<const char*>(buffer);
   while (remaining > 0) {
-    int bytes_read = Write(current_buffer, remaining);
+    int64_t bytes_read = Write(current_buffer, remaining);
     if (bytes_read < 0) {
       return false;
     }
     remaining -= bytes_read;  // Reduce the number of remaining bytes.
     current_buffer += bytes_read;  // Move the buffer forward.
   }
   return true;
 }
 
 
@@ skipping 1125 matching lines @@
     CObjectArray* wrapper = new CObjectArray(CObject::NewArray(2));
     wrapper->SetAt(0, new CObjectInt32(CObject::NewInt32(CObject::kSuccess)));
     wrapper->SetAt(1, result);
     return wrapper;
   }
   return CObject::IllegalArgumentError();
 }
 
 }  // namespace bin
 }  // namespace dart