Move unique name generation and tracking into //content.

third_party/WebKit/Source/core/loader/HistoryItem.cpp

Index: third_party/WebKit/Source/core/loader/HistoryItem.cpp
diff --git a/third_party/WebKit/Source/core/loader/HistoryItem.cpp b/third_party/WebKit/Source/core/loader/HistoryItem.cpp
index 97aeb25898dc6db10eea98b0d2bc8dc404ba0861..8e68e7c0c552391803e5e859661d4c4bc4dbcfe5 100644
--- a/third_party/WebKit/Source/core/loader/HistoryItem.cpp
+++ b/third_party/WebKit/Source/core/loader/HistoryItem.cpp
@@ -63,10 +63,6 @@ const Referrer& HistoryItem::referrer() const {
   return m_referrer;
 }
 
-const String& HistoryItem::target() const {
-  return m_target;
-}
-
 void HistoryItem::setURLString(const String& urlString) {
   if (m_urlString != urlString)
     m_urlString = urlString;
@@ -82,10 +78,6 @@ void HistoryItem::setReferrer(const Referrer& referrer) {
                                                 referrer.referrer);
 }
 
-void HistoryItem::setTarget(const String& target) {
-  m_target = target;
-}
-
 const ScrollOffset& HistoryItem::visualViewportScrollOffset() const {
   return m_visualViewportScrollOffset;
 }