Remove mail blockquote special case handling.

Source/WebCore/editing/EditorCommand.cpp

Index: Source/WebCore/editing/EditorCommand.cpp
diff --git a/Source/WebCore/editing/EditorCommand.cpp b/Source/WebCore/editing/EditorCommand.cpp
index 3c5f0a68e1ae03efad012549deb09d6dfad8e575..d2a21b636de021d2edfcbad24aa34fe787ab9e77 100644
--- a/Source/WebCore/editing/EditorCommand.cpp
+++ b/Source/WebCore/editing/EditorCommand.cpp
@@ -531,12 +531,6 @@ static bool executeInsertNewline(Frame* frame, Event* event, EditorCommandSource
     return targetFrame->eventHandler()->handleTextInputEvent("\n", event, targetFrame->editor()->canEditRichly() ? TextEventInputKeyboard : TextEventInputLineBreak);
 }
 
-static bool executeInsertNewlineInQuotedContent(Frame* frame, Event*, EditorCommandSource, const String&)
-{
-    TypingCommand::insertParagraphSeparatorInQuotedContent(frame->document());
-    return true;
-}
-
 static bool executeInsertOrderedList(Frame* frame, Event*, EditorCommandSource, const String&)
 {
     applyCommand(InsertListCommand::create(frame->document(), InsertListCommand::OrderedList));
@@ -1495,7 +1489,6 @@ static const CommandMap& createCommandMap()
         { "InsertImage", { executeInsertImage, supported, enabledInRichlyEditableText, stateNone, valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled } },
         { "InsertLineBreak", { executeInsertLineBreak, supported, enabledInEditableText, stateNone, valueNull, isTextInsertion, doNotAllowExecutionWhenDisabled } },
         { "InsertNewline", { executeInsertNewline, supportedFromMenuOrKeyBinding, enabledInEditableText, stateNone, valueNull, isTextInsertion, doNotAllowExecutionWhenDisabled } },    
-        { "InsertNewlineInQuotedContent", { executeInsertNewlineInQuotedContent, supported, enabledInRichlyEditableText, stateNone, valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled } },
         { "InsertOrderedList", { executeInsertOrderedList, supported, enabledInRichlyEditableText, stateOrderedList, valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled } },
         { "InsertParagraph", { executeInsertParagraph, supported, enabledInEditableText, stateNone, valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled } },
         { "InsertTab", { executeInsertTab, supportedFromMenuOrKeyBinding, enabledInEditableText, stateNone, valueNull, isTextInsertion, doNotAllowExecutionWhenDisabled } },