Split user agent code out of the 'glue' target

webkit/glue/user_agent.cc

 // Copyright (c) 2012 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
 
 #include "base/lazy_instance.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
+#include "base/synchronization/lock.h"
 #include "base/sys_info.h"
+#include "googleurl/src/gurl.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #endif
 
 // Generated
 #include "webkit_version.h"  // NOLINT
 
+namespace {
+
+class UserAgentState {
+ public:
+  UserAgentState();
+  ~UserAgentState();
+
+  void Set(const std::string& user_agent, bool overriding);
+  const std::string& Get(const GURL& url) const;
+
+ private:
+  mutable std::string user_agent_;
+  // The UA string when we're pretending to be Mac Safari or Win Firefox.
+  mutable std::string user_agent_for_spoofing_hack_;
+
+  mutable bool user_agent_requested_;
+  bool user_agent_is_overridden_;
+
+  // This object can be accessed from multiple threads, so use a lock around
+  // accesses to the data members.
+  mutable base::Lock lock_;
+};
+
+UserAgentState::UserAgentState()
+    : user_agent_requested_(false),
+      user_agent_is_overridden_(false) {
+}
+
+UserAgentState::~UserAgentState() {
+}
+
+void UserAgentState::Set(const std::string& user_agent, bool overriding) {
+  base::AutoLock auto_lock(lock_);
+  if (user_agent == user_agent_) {
+    // We allow the user agent to be set multiple times as long as it
+    // is set to the same value, in order to simplify unit testing
+    // given g_user_agent is a global.
+    return;
+  }
+  DCHECK(!user_agent.empty());
+  DCHECK(!user_agent_requested_) << "Setting the user agent after someone has "
+      "already requested it can result in unexpected behavior.";
+  user_agent_is_overridden_ = overriding;
+  user_agent_ = user_agent;
+}
+
+bool IsMicrosoftSiteThatNeedsSpoofingForSilverlight(const GURL& url) {
+#if defined(OS_MACOSX)
+  // The landing page for updating Silverlight gives a confusing experience
+  // in browsers that Silverlight doesn't officially support; spoof as
+  // Safari to reduce the chance that users won't complete updates.
+  // Should be removed if the sniffing is removed: http://crbug.com/88211
+  if (url.host() == "www.microsoft.com" &&
+      StartsWithASCII(url.path(), "/getsilverlight", false)) {
+    return true;
+  }
+#endif
+  return false;
+}
+
+bool IsYahooSiteThatNeedsSpoofingForSilverlight(const GURL& url) {
+#if defined(OS_MACOSX) || defined(OS_WIN)
+  // The following Yahoo! JAPAN pages erroneously judge that Silverlight does
+  // not support Chromium. Until the pages are fixed, spoof the UA.
+  // http://crbug.com/104426
+  if (url.host() == "headlines.yahoo.co.jp" &&
+      StartsWithASCII(url.path(), "/videonews/", true)) {
+    return true;
+  }
+#endif
+#if defined(OS_MACOSX)
+  if ((url.host() == "downloads.yahoo.co.jp" &&
+      StartsWithASCII(url.path(), "/docs/silverlight/", true)) ||
+      url.host() == "gyao.yahoo.co.jp") {
+    return true;
+  }
+#elif defined(OS_WIN)
+  if ((url.host() == "weather.yahoo.co.jp" &&
+        StartsWithASCII(url.path(), "/weather/zoomradar/", true)) ||
+      url.host() == "promotion.shopping.yahoo.co.jp" ||
+      url.host() == "pokemon.kids.yahoo.co.jp") {
+    return true;
+  }
+#endif
+  return false;
+}
+
+const std::string& UserAgentState::Get(const GURL& url) const {
+  base::AutoLock auto_lock(lock_);
+  user_agent_requested_ = true;
+
+  DCHECK(!user_agent_.empty());
+
+  // Workarounds for sites that use misguided UA sniffing.
+  if (!user_agent_is_overridden_) {
+    if (IsMicrosoftSiteThatNeedsSpoofingForSilverlight(url) ||
+        IsYahooSiteThatNeedsSpoofingForSilverlight(url)) {
+      if (user_agent_for_spoofing_hack_.empty()) {
+#if defined(OS_MACOSX)
+        user_agent_for_spoofing_hack_ = webkit_glue::BuildUserAgentFromProduct(
+            "Version/5.1.1 Safari/534.51.22");
+#elif defined(OS_WIN)
+        // Pretend to be Firefox. Silverlight doesn't support Win Safari.
+        base::StringAppendF(
+            &user_agent_for_spoofing_hack_,
+            "Mozilla/5.0 (%s) Gecko/20100101 Firefox/8.0",
+            webkit_glue::BuildOSCpuInfo().c_str());
+#endif
+      }
+      DCHECK(!user_agent_for_spoofing_hack_.empty());
+      return user_agent_for_spoofing_hack_;
+    }
+  }
+
+  return user_agent_;
+}
+
+base::LazyInstance<UserAgentState> g_user_agent = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
 namespace webkit_glue {
 
+void SetUserAgent(const std::string& user_agent, bool overriding) {
+  g_user_agent.Get().Set(user_agent, overriding);
+}
+
+const std::string& GetUserAgent(const GURL& url) {
+  return g_user_agent.Get().Get(url);
+}
+
 std::string GetWebKitVersion() {
   return base::StringPrintf("%d.%d (%s)",
                             WEBKIT_VERSION_MAJOR,
                             WEBKIT_VERSION_MINOR,
                             WEBKIT_SVN_REVISION);
 }
 
 std::string GetWebKitRevision() {
   return WEBKIT_SVN_REVISION;
 }
@@ skipping 134 matching lines @@
       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