diff --git a/dom/base/nsDOMClassInfo.cpp b/dom/base/nsDOMClassInfo.cpp
index 43c80b78a217..8f25dfa3c6fd 100644
--- a/dom/base/nsDOMClassInfo.cpp
+++ b/dom/base/nsDOMClassInfo.cpp
@@ -8120,7 +8120,7 @@ nsDOMStringMapSH::Enumerate(nsIXPConnectWrappedNative *wrapper, JSContext *cx,
   NS_ENSURE_SUCCESS(rv, rv);
 
   for (PRUint32 i = 0; i < properties.Length(); ++i) {
-    nsString& prop(properties[i]);
+    nsDependentString prop(properties[i]);
     *_retval = JS_DefineUCProperty(cx, obj, prop.get(), prop.Length(),
                                    JSVAL_VOID, nsnull, nsnull,
                                    JSPROP_ENUMERATE | JSPROP_SHARED);
diff --git a/layout/style/nsCSSValue.cpp b/layout/style/nsCSSValue.cpp
index a303eff13364..6fd4e0c2993b 100644
--- a/layout/style/nsCSSValue.cpp
+++ b/layout/style/nsCSSValue.cpp
@@ -922,7 +922,8 @@ nsCSSValue::AppendToString(nsCSSProperty aProperty, nsAString& aResult) const
     aResult.Append(NS_LITERAL_STRING("-moz-element(#"));
     nsAutoString tmpStr;
     GetStringValue(tmpStr);
-    nsStyleUtil::AppendEscapedCSSIdent(tmpStr, aResult);
+    nsStyleUtil::AppendEscapedCSSIdent(
+      nsDependentString(tmpStr), aResult);
     aResult.Append(NS_LITERAL_STRING(")"));
   }
   else if (eCSSUnit_Percent == unit) {
diff --git a/netwerk/cookie/CookieServiceParent.cpp b/netwerk/cookie/CookieServiceParent.cpp
index c2d3185c4a7e..47e72da16f19 100644
--- a/netwerk/cookie/CookieServiceParent.cpp
+++ b/netwerk/cookie/CookieServiceParent.cpp
@@ -95,9 +95,8 @@ CookieServiceParent::RecvSetCookieString(const IPC::URI& aHost,
   if (!hostURI)
     return false;
 
-  nsDependentCString cookieString(aCookieString, 0);
   mCookieService->SetCookieStringInternal(hostURI, aIsForeign,
-                                          cookieString, aServerTime,
+                                          aCookieString, aServerTime,
                                           aFromHttp);
   return true;
 }
diff --git a/netwerk/cookie/nsCookieService.cpp b/netwerk/cookie/nsCookieService.cpp
index 93d4da4348ee..5893a06551df 100644
--- a/netwerk/cookie/nsCookieService.cpp
+++ b/netwerk/cookie/nsCookieService.cpp
@@ -1493,11 +1493,11 @@ nsCookieService::SetCookieStringCommon(nsIURI *aHostURI,
 }
 
 void
-nsCookieService::SetCookieStringInternal(nsIURI             *aHostURI,
-                                         bool                aIsForeign,
-                                         nsDependentCString &aCookieHeader,
-                                         const nsCString    &aServerTime,
-                                         PRBool              aFromHttp)
+nsCookieService::SetCookieStringInternal(nsIURI          *aHostURI,
+                                         bool             aIsForeign,
+                                         const nsCString &aCookieHeader,
+                                         const nsCString &aServerTime,
+                                         PRBool           aFromHttp) 
 {
   NS_ASSERTION(aHostURI, "null host!");
 
@@ -1550,8 +1550,9 @@ nsCookieService::SetCookieStringInternal(nsIURI             *aHostURI,
   }
 
   // process each cookie in the header
-  while (SetCookieInternal(aHostURI, baseDomain, requireHostMatch, cookieStatus,
-                           aCookieHeader, serverTime, aFromHttp)) {
+  nsDependentCString cookieHeader(aCookieHeader);
+  while (SetCookieInternal(aHostURI, baseDomain, requireHostMatch,
+                           cookieStatus, cookieHeader, serverTime, aFromHttp)) {
     // document.cookie can only set one cookie at a time
     if (!aFromHttp)
       break;
diff --git a/netwerk/cookie/nsCookieService.h b/netwerk/cookie/nsCookieService.h
index 267ce7bc61e6..6fced2621b04 100644
--- a/netwerk/cookie/nsCookieService.h
+++ b/netwerk/cookie/nsCookieService.h
@@ -263,7 +263,7 @@ class nsCookieService : public nsICookieService
     nsresult                      GetCookieStringCommon(nsIURI *aHostURI, nsIChannel *aChannel, bool aHttpBound, char** aCookie);
     void                          GetCookieStringInternal(nsIURI *aHostURI, bool aIsForeign, PRBool aHttpBound, nsCString &aCookie);
     nsresult                      SetCookieStringCommon(nsIURI *aHostURI, const char *aCookieHeader, const char *aServerTime, nsIChannel *aChannel, bool aFromHttp);
-    void                          SetCookieStringInternal(nsIURI *aHostURI, bool aIsForeign, nsDependentCString &aCookieHeader, const nsCString &aServerTime, PRBool aFromHttp);
+    void                          SetCookieStringInternal(nsIURI *aHostURI, bool aIsForeign, const nsCString &aCookieHeader, const nsCString &aServerTime, PRBool aFromHttp);
     PRBool                        SetCookieInternal(nsIURI *aHostURI, const nsCString& aBaseDomain, PRBool aRequireHostMatch, CookieStatus aStatus, nsDependentCString &aCookieHeader, PRInt64 aServerTime, PRBool aFromHttp);
     void                          AddInternal(const nsCString& aBaseDomain, nsCookie *aCookie, PRInt64 aCurrentTimeInUsec, nsIURI *aHostURI, const char *aCookieHeader, PRBool aFromHttp);
     void                          RemoveCookieFromList(const nsListIter &aIter, mozIStorageBindingParamsArray *aParamsArray = NULL);
diff --git a/widget/src/xpwidgets/nsXPLookAndFeel.cpp b/widget/src/xpwidgets/nsXPLookAndFeel.cpp
index d106e73bde4b..e698a1c4e776 100644
--- a/widget/src/xpwidgets/nsXPLookAndFeel.cpp
+++ b/widget/src/xpwidgets/nsXPLookAndFeel.cpp
@@ -330,7 +330,9 @@ nsXPLookAndFeel::ColorPrefChanged (unsigned int index, const char *prefName)
   if (!colorStr.IsEmpty()) {
     nscolor thecolor;
     if (colorStr[0] == PRUnichar('#')) {
-      if (NS_HexToRGB(nsDependentString(colorStr, 1), &thecolor)) {
+      if (NS_HexToRGB(nsDependentString(
+                        Substring(colorStr, 1, colorStr.Length() - 1)),
+                      &thecolor)) {
         PRInt32 id = NS_PTR_TO_INT32(index);
         CACHE_COLOR(id, thecolor);
       }
diff --git a/xpcom/string/public/nsTDependentString.h b/xpcom/string/public/nsTDependentString.h
index 818f7200d031..a9192e02a4c2 100644
--- a/xpcom/string/public/nsTDependentString.h
+++ b/xpcom/string/public/nsTDependentString.h
@@ -91,10 +91,11 @@ class nsTDependentString_CharT : public nsTString_CharT
           AssertValid();
         }
 
-      nsTDependentString_CharT( const string_type& str, PRUint32 startPos )
-        : string_type()
+      explicit
+      nsTDependentString_CharT( const substring_type& str )
+        : string_type(const_cast<char_type*>(str.Data()), str.Length(), F_TERMINATED)
         {
-          Rebind(str, startPos);
+          AssertValid();
         }
 
       // Create a nsTDependentSubstring to be bound later
@@ -123,8 +124,6 @@ class nsTDependentString_CharT : public nsTString_CharT
           Rebind(start, PRUint32(end - start));
         }
 
-      void Rebind( const string_type&, PRUint32 startPos );
-
     private:
       
       // NOT USED
diff --git a/xpcom/string/src/nsTDependentString.cpp b/xpcom/string/src/nsTDependentString.cpp
index 88a41f448fdb..f1dd21cc9262 100644
--- a/xpcom/string/src/nsTDependentString.cpp
+++ b/xpcom/string/src/nsTDependentString.cpp
@@ -48,20 +48,3 @@ nsTDependentString_CharT::Rebind( const char_type* data, size_type length )
     SetDataFlags(F_TERMINATED);
     AssertValid();
   }
-
-void
-nsTDependentString_CharT::Rebind( const string_type& str, PRUint32 startPos )
-  {
-    // If we currently own a buffer, release it.
-    Finalize();
-
-    size_type strLength = str.Length();
-
-    if (startPos > strLength)
-      startPos = strLength;
-
-    mData = const_cast<char_type*>(str.Data()) + startPos;
-    mLength = strLength - startPos;
-
-    SetDataFlags(F_TERMINATED);
-  }