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

chrome/common/extensions/extension_icon_set.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/extension_icon_set.h"
 
 #include "base/logging.h"
 
 ExtensionIconSet::ExtensionIconSet() {}
 
 ExtensionIconSet::~ExtensionIconSet() {}
 
 void ExtensionIconSet::Clear() {
   map_.clear();
 }
 
 void ExtensionIconSet::Add(int size, const std::string& path) {
-  CHECK(path.size() > 0 && path[0] != '/');
+  CHECK(!path.empty() && path[0] != '/');
   map_[size] = path;
 }
 
 std::string ExtensionIconSet::Get(int size, MatchType match_type) const {
   // The searches for MATCH_BIGGER and MATCH_SMALLER below rely on the fact that
   // std::map is sorted. This is per the spec, so it should be safe to rely on.
   if (match_type == MATCH_EXACTLY) {
     IconMap::const_iterator result = map_.find(size);
     return result == map_.end() ? std::string() : result->second;
   } else if (match_type == MATCH_SMALLER) {
@@ skipping 28 matching lines @@
       "ExtensionIconSet stores icon paths without leading slash.";
 
   for (IconMap::const_iterator iter = map_.begin(); iter != map_.end();
        ++iter) {
     if (iter->second == path)
       return true;
   }
 
   return false;
 }