Revert "Remove webkit_glue::BuildUserAgent(), change the contract in webkit_glue"

webkit/glue/user_agent.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 "webkit/glue/user_agent.h"
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 #include <sys/utsname.h>
 #endif
 
@@ skipping 95 matching lines @@
 }
 
 int GetWebKitMajorVersion() {
   return WEBKIT_VERSION_MAJOR;
 }
 
 int GetWebKitMinorVersion() {
   return WEBKIT_VERSION_MINOR;
 }
 
-std::string BuildUserAgentFromProduct(const std::string& product) {
+std::string BuildUserAgentHelper(bool mimic_windows,
+                                 const std::string& product) {
   const char kUserAgentPlatform[] =
 #if defined(OS_WIN)
       "";
 #elif defined(OS_MACOSX)
       "Macintosh; ";
 #elif defined(USE_X11)
       "X11; ";           // strange, but that's what Firefox uses
 #else
       "Unknown; ";
 #endif
 
   std::string user_agent;
 
+  // Replace Safari's Version/X string with the product name/version passed in.
   // This is done to expose our product name in a manner that is maximally
   // compatible with Safari, we hope!!
 
   // Derived from Safari's UA string.
   base::StringAppendF(
       &user_agent,
       "Mozilla/5.0 (%s%s) AppleWebKit/%d.%d"
       " (KHTML, like Gecko) %s Safari/%d.%d",
-      kUserAgentPlatform,
+      mimic_windows ? "Windows " : kUserAgentPlatform,
       webkit_glue::BuildOSCpuInfo().c_str(),
       WEBKIT_VERSION_MAJOR,
       WEBKIT_VERSION_MINOR,
       product.c_str(),
       WEBKIT_VERSION_MAJOR,
       WEBKIT_VERSION_MINOR);
   return user_agent;
 }
 
 }  // namespace webkit_glue