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

chrome/browser/autocomplete/autocomplete_match.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 "base/logging.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
 #include "grit/theme_resources.h"
 
 // AutocompleteMatch ----------------------------------------------------------
 
@@ skipping 148 matching lines @@
 
 void AutocompleteMatch::ValidateClassifications(
     const string16& text,
     const ACMatchClassifications& classifications) const {
   if (text.empty()) {
     DCHECK(classifications.size() == 0);
     return;
   }
 
   // The classifications should always cover the whole string.
-  DCHECK(classifications.size() > 0) << "No classification for text";
+  DCHECK(!classifications.empty()) << "No classification for text";
   DCHECK(classifications[0].offset == 0) << "Classification misses beginning";
   if (classifications.size() == 1)
     return;
 
   // The classifications should always be sorted.
   size_t last_offset = classifications[0].offset;
   for (ACMatchClassifications::const_iterator i(classifications.begin() + 1);
        i != classifications.end(); ++i) {
     DCHECK(i->offset > last_offset) << "Classification unsorted";
     DCHECK(i->offset < text.length()) << "Classification out of bounds";
     last_offset = i->offset;
   }
 }
 #endif