[Android] Fix gn build for instrumentation tests.

tools/android/forwarder2/socket.cc

 // Copyright (c) 2012 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.
 
 #include "tools/android/forwarder2/socket.h"
 
 #include <arpa/inet.h>
 #include <fcntl.h>
 #include <netdb.h>
 #include <netinet/in.h>
@@ skipping 273 matching lines @@
 
 int Socket::GetPort() {
   if (!FamilyIsTCP(family_)) {
     LOG(ERROR) << "Can't call GetPort() on an unix domain socket.";
     return 0;
   }
   return port_;
 }
 
 int Socket::ReadNumBytes(void* buffer, size_t num_bytes) {
-  int bytes_read = 0;
+  size_t bytes_read = 0;
   int ret = 1;
   while (bytes_read < num_bytes && ret > 0) {
     ret = Read(static_cast<char*>(buffer) + bytes_read, num_bytes - bytes_read);
     if (ret >= 0)
       bytes_read += ret;
   }
   return bytes_read;
 }
 
 void Socket::SetSocketError() {
@@ skipping 68 matching lines @@
 }
 
 bool Socket::DidReceiveEvent() const {
   for (size_t i = 0; i < events_.size(); ++i)
     if (events_[i].was_fired)
       return true;
   return false;
 }
 
 int Socket::WriteNumBytes(const void* buffer, size_t num_bytes) {
-  int bytes_written = 0;
+  size_t bytes_written = 0;
   int ret = 1;
   while (bytes_written < num_bytes && ret > 0) {
     ret = Write(static_cast<const char*>(buffer) + bytes_written,
                 num_bytes - bytes_written);
     if (ret >= 0)
       bytes_written += ret;
   }
   return bytes_written;
 }
 
@@ skipping 45 matching lines @@
   ucred ucred;
   socklen_t len = sizeof(ucred);
   if (getsockopt(socket.socket_, SOL_SOCKET, SO_PEERCRED, &ucred, &len) == -1) {
     CHECK_NE(ENOPROTOOPT, errno);
     return -1;
   }
   return ucred.pid;
 }
 
 }  // namespace forwarder2