Reviewed by Ryosuke Niwa.

        Space and tab characters "sent" by an input method give totally different results than typing them directly.
        https://bugs.webkit.org/show_bug.cgi?id=5241

        Added a test that exercises continous whitespace characters and tabs inserted by IME.

        * editing/inserting/insert-composition-whitespace-expected.txt: Added.
        * editing/inserting/insert-composition-whitespace.html: Added.
2011-01-19  MORITA Hajime  <morrita@google.com>

        Reviewed by Ryosuke Niwa.

        Space and tab characters "sent" by an input method give totally different results than typing them directly
        https://bugs.webkit.org/show_bug.cgi?id=5241

        * Introduced TextEvent::InputTypeComposition and TypingCommand::TextCompositionType to
          distinguish text input which is originated by composition.
        * Generalized rebalanceWhitespaceAt() to rebalanceWhitespaceOnTextSubstring() to rebalancing
          range of string on text node, instead of surrounding part of that.

        Test: editing/inserting/insert-composition-whitespace.html

        * dom/TextEvent.h:
        (WebCore::TextEvent::isComposition):
        * dom/TextEventInputType.h: Added TextEventInputComposition as a member of TextEvent::InputType
        * editing/CompositeEditCommand.cpp:
        (WebCore::containsOnlyWhitespace):
        (WebCore::CompositeEditCommand::shouldRebalanceLeadingWhitespaceFor):
        (WebCore::CompositeEditCommand::canRebalance):
        (WebCore::CompositeEditCommand::rebalanceWhitespaceAt):
        (WebCore::CompositeEditCommand::rebalanceWhitespaceOnTextSubstring): Added: A generalized version of rebalanceWhitespaceAt(), which takes a range inside Text string.
        * editing/CompositeEditCommand.h:
        * editing/Editor.cpp:
        (WebCore::Editor::insertTextForConfirmedComposition): Added.
        (WebCore::Editor::insertTextWithoutSendingTextEvent):
        (WebCore::Editor::confirmComposition): Now uses insertTextForConfirmedComposition().
        (WebCore::Editor::setComposition):
        * editing/Editor.h:
        * editing/InsertTextCommand.cpp:
        (WebCore::InsertTextCommand::input):
        * editing/InsertTextCommand.h:
        * editing/TypingCommand.cpp:
        (WebCore::TypingCommand::TypingCommand):
        (WebCore::TypingCommand::insertText):
        (WebCore::TypingCommand::insertTextRunWithoutNewlines):
        * editing/TypingCommand.h: Added TypingCommand::m_compositionType and TypingCommand::TextCompositionType
        (WebCore::TypingCommand::setCompositionType): Added.
        (WebCore::TypingCommand::create):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@76215 268f45cc-cd09-0410-ab3c-d52691b4dbfc