Makes it so select tag are monolithic, this means the sink doesn't get flushed

until the end tag of a select. This helps performance a great deal. If it gets flushed
inbetween then the remaining options are added one at a time using the AddOption
and this is a lot less effecient.
b 28593, r=vidur

content/html/document/src/nsHTMLContentSink.cpp

@@ -3931,7 +3931,7 @@ HTMLContentSink::NotifyInsert(nsIContent* aContent,
 PRBool 
 HTMLContentSink::IsMonolithicContainer(nsHTMLTag aTag)
 {
-  if (eHTMLTag_tr == aTag) {
+  if (eHTMLTag_tr == aTag || eHTMLTag_select == aTag) {
     return PR_TRUE;
   }
   else {

layout/html/document/src/nsHTMLContentSink.cpp

@@ -3931,7 +3931,7 @@ HTMLContentSink::NotifyInsert(nsIContent* aContent,
 PRBool 
 HTMLContentSink::IsMonolithicContainer(nsHTMLTag aTag)
 {
-  if (eHTMLTag_tr == aTag) {
+  if (eHTMLTag_tr == aTag || eHTMLTag_select == aTag) {
     return PR_TRUE;
   }
   else {