Use built-in size function from std::string instead of strlen function.

chrome/plugin/plugin_main_mac.mm

 // Copyright (c) 2010 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 "base/chrome_application_mac.h"
 #include "base/environment.h"
 #include "base/scoped_ptr.h"
 #include "base/string_util.h"
 #include "chrome/common/plugin_carbon_interpose_constants_mac.h"
 #include "chrome/plugin/plugin_interpose_util_mac.h"
 
 #if !defined(__LP64__)
 void TrimInterposeEnvironment() {
   scoped_ptr<base::Environment> env(base::Environment::Create());
 
   std::string interpose_list;
   if (!env->GetEnv(plugin_interpose_strings::kDYLDInsertLibrariesKey,
                    &interpose_list)) {
     NOTREACHED() << "No interposing libraries set";
     return;
   }
 
   // The list is a :-separated list of paths. Because we append our interpose
   // library just before forking in plugin_process_host.cc, the only cases we
   // need to handle are:
   // 1) The whole string is "<kInterposeLibraryPath>", so just clear it, or
   // 2) ":<kInterposeLibraryPath>" is the end of the string, so trim and re-set.
-  int suffix_offset = strlen(interpose_list.c_str()) -
-      strlen(plugin_interpose_strings::kInterposeLibraryPath);
-
+  std::string interpose_library_path(
+      plugin_interpose_strings::kInterposeLibraryPath);
+  DCHECK_GE(interpose_list.size(), interpose_library_path.size());
+  size_t suffix_offset = interpose_list.size() - interpose_library_path.size();
   if (suffix_offset == 0 &&
-      strcmp(interpose_list.c_str(),
-             plugin_interpose_strings::kInterposeLibraryPath) == 0) {
+      interpose_list == interpose_library_path) {
     env->UnSetVar(plugin_interpose_strings::kDYLDInsertLibrariesKey);
   } else if (suffix_offset > 0 && interpose_list[suffix_offset - 1] == ':' &&
-             strcmp(interpose_list.c_str() + suffix_offset,
-                    plugin_interpose_strings::kInterposeLibraryPath) == 0) {
+             interpose_list.substr(suffix_offset) == interpose_library_path) {
     std::string trimmed_list = interpose_list.substr(0, suffix_offset - 1);
     env->SetEnv(plugin_interpose_strings::kDYLDInsertLibrariesKey,
                 trimmed_list.c_str());
   } else {
     NOTREACHED() << "Missing Carbon interposing library";
   }
 }
 #endif
 
 void InitializeChromeApplication() {
   [CrApplication sharedApplication];
 
   mac_plugin_interposing::SetUpCocoaInterposing();
 }