Fix gcc 4.6 compile issues; set but unused variable and pointer/FALSE fubar.

chrome/browser/chromeos/external_metrics_unittest.cc

 // Copyright (c) 2011 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 <errno.h>
 #include <sys/file.h>
 
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/external_metrics.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace chromeos {  // Need this because of the FRIEND_TEST
 
 class ExternalMetricsTest : public testing::Test {
 };
 
 // Because the metrics service is not essential, errors will not cause the
 // program to terminate.  However, the errors produce logs.
 
 #define MAXLENGTH ExternalMetrics::kMetricsMessageMaxLength
 
 static void SendMessage(const char* path, const char* name, const char* value) {
   int fd = open(path, O_CREAT | O_APPEND | O_WRONLY, 0666);
   int32 l = strlen(name) + strlen(value) + 2 + sizeof(l);
-  int num_bytes;
-  num_bytes = write(fd, &l, sizeof(l));
-  num_bytes = write(fd, name, strlen(name) + 1);
-  num_bytes = write(fd, value, strlen(value) + 1);
+  size_t num_bytes = 0;
+  num_bytes += write(fd, &l, sizeof(l));
+  num_bytes += write(fd, name, strlen(name) + 1);
+  num_bytes += write(fd, value, strlen(value) + 1);
+  EXPECT_EQ(num_bytes, sizeof(l) + strlen(name) + strlen(value) + 2);
   close(fd);
 }
 
 static scoped_ptr<std::string> received_name;
 static scoped_ptr<std::string> received_value;
 int received_count = 0;
 
 static void ReceiveMessage(const char* name, const char* value) {
   received_name.reset(new std::string(name));
   received_value.reset(new std::string(value));
@@ skipping 85 matching lines @@
   external_metrics->CollectEvents();
   EXPECT_EQ(expect_count, received_count);
 
   // Checks that we survive when file doesn't exist.
   EXPECT_EQ(0, unlink(path));
   external_metrics->CollectEvents();
   EXPECT_EQ(expect_count, received_count);
 }
 
 }  // namespace chromeos