Change other usages of .size() to .empty() when applicable.

chrome/common/extensions/update_manifest.cc

 // 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 "chrome/common/extensions/update_manifest.h"
 
 #include <algorithm>
 
 #include "base/scoped_ptr.h"
 #include "base/stl_util-inl.h"
@@ skipping 224 matching lines @@
 
   // Check for the gupdate "protocol" attribute.
   if (GetAttribute(root, "protocol") != kExpectedGupdateProtocol) {
     ParseError("Missing/incorrect protocol on gupdate tag "
         "(expected '%s')", kExpectedGupdateProtocol);
     return false;
   }
 
   // Parse the first <daystart> if it's present.
   std::vector<xmlNode*> daystarts = GetChildren(root, gupdate_ns, "daystart");
-  if (daystarts.size() > 0) {
+  if (!daystarts.empty()) {
     xmlNode* first = daystarts[0];
     std::string elapsed_seconds = GetAttribute(first, "elapsed_seconds");
     int parsed_elapsed = kNoDaystart;
     if (base::StringToInt(elapsed_seconds, &parsed_elapsed)) {
       results_.daystart_elapsed_seconds = parsed_elapsed;
     }
   }
 
   // Parse each of the <app> tags.
   std::vector<xmlNode*> apps = GetChildren(root, gupdate_ns, "app");
   for (unsigned int i = 0; i < apps.size(); i++) {
     Result current;
     std::string error;
     if (!ParseSingleAppTag(apps[i], gupdate_ns, &current, &error)) {
       ParseError("%s", error.c_str());
     } else {
       results_.list.push_back(current);
     }
   }
 
   return true;
 }