Remove a bunch of TOOLKIT_GTK in content/ and gpu/, as well as NPAPI plugins on linux

content/public/common/common_param_traits.h

Index: content/public/common/common_param_traits.h
diff --git a/content/public/common/common_param_traits.h b/content/public/common/common_param_traits.h
index 8800fe12194e972058a0922b8be083cb0f199de3..f527f1628008cb96cd598d2ed1e1664c294f7353 100644
--- a/content/public/common/common_param_traits.h
+++ b/content/public/common/common_param_traits.h
@@ -204,24 +204,6 @@ struct ParamTraits<TransportDIB::Id> {
 };
 #endif
 
-#if defined(TOOLKIT_GTK)
-template<>
-struct ParamTraits<TransportDIB::Id> {
-  typedef TransportDIB::Id param_type;
-  static void Write(Message* m, const param_type& p) {
-    WriteParam(m, p.shmkey);
-  }
-  static bool Read(const Message* m, PickleIterator* iter, param_type* r) {
-    return ReadParam(m, iter, &r->shmkey);
-  }
-  static void Log(const param_type& p, std::string* l) {
-    l->append("TransportDIB(");
-    LogParam(p.shmkey, l);
-    l->append(")");
-  }
-};
-#endif
-
 template <>
 struct CONTENT_EXPORT ParamTraits<SkBitmap> {
   typedef SkBitmap param_type;