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

chrome/browser/ui/webui/bug_report_ui.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 "chrome/browser/ui/webui/bug_report_ui.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 615 matching lines @@
     return;
   }
 
   // #3 -  Screenshot to send.
   std::string screenshot_path;
   (*i)->GetAsString(&screenshot_path);
   screenshot_path.erase(0, strlen(kScreenshotBaseUrl));
 
   // Get the image to send in the report.
   std::vector<unsigned char> image;
-  if (screenshot_path.size() > 0) {
+  if (!screenshot_path.empty())
     image = screenshot_source_->GetScreenshot(screenshot_path);
-  }
 
 #if defined(OS_CHROMEOS)
   if (++i == list_value->end()) {
     LOG(ERROR) << "Incorrect data passed to sendReport.";
     return;
   }
 
   // #4 - User e-mail
   std::string user_email;
   (*i)->GetAsString(&user_email);
@@ skipping 87 matching lines @@
   BugReportHandler* handler = new BugReportHandler(tab);
   AddMessageHandler((handler)->Attach(this));
 
   // The handler's init will specify which html
   // resource we'll display to the user
   BugReportUIHTMLSource* html_source =
       new BugReportUIHTMLSource(handler->Init());
   // Set up the chrome://bugreport/ source.
   tab->profile()->GetChromeURLDataManager()->AddDataSource(html_source);
 }