Reviewed by Adam.

        - re-speed-up the page load test (my StringImpl change slowed it down)

        * wtf/RefCounted.h:
        (WTF::RefCounted::RefCounted): Allow derived classes to start with a reference
        count other than 0. Eventually everyone will want to start with a 1. This is a
        staged change. For now, there's a default of 0, and you can specify 1. Later,
        there will be no default and everyone will have to specify. And then later, there
        will be a default of 1. Eventually, we can take away even the option of starting
        with 0!

        * wtf/Vector.h:
        (WTF::Vector::Vector): Sped up creation of non-empty vectors by removing the
        overhead of first constructing something empty and then calling resize.
        (WTF::Vector::clear): Sped up the common case of calling clear on an empty
        vector by adding a check for that case.
        (WTF::Vector::releaseBuffer): Marked this function inline and removed a branch
        in the case of vectors with no inline capacity (normal vectors) by leaving out
        the code to copy the inline buffer in that case.

WebCore:

        Reviewed by Adam.

        - re-speed-up the page load test (my StringImpl change slowed it down)
          <rdar://problem/5677241> 1.5% PLT regression from r29098

        To reverse the slowdown I caused by changing StringImpl, I tightened it up,
        and also did a little optimization in the HTML tokenizer and in other clients
        of Vector.

        * WebCore.base.exp: Removed export of a now-inline function.

        * css/CSSParser.cpp:
        (WebCore::CSSParser::parseTransitionProperty): Removed use of DeprecatedString
        to get property ID. This could be sped up even more by writing a fast path
        to use a local Vector<char> rather than allocating a string.
        (WebCore::convertASCIIToFloat): Added. Allows numeric conversion without
        allocating a string object to hold the number.
        (WebCore::CSSParser::lex): Changed to call convertASCIIToFloat instead of
        DeprecatedString::toFloat.

        * dom/Element.h:
        (WebCore::Element::hasTagName): Made this non-virtual and inline if you have
        an Element*. It's still virtual if you have a Node*.
        (WebCore::Element::virtualHasTagName): Virtual version that makes the Node*
        case work.

        * dom/Node.h:
        (WebCore::Node::hasTagName): Made this non-virtual and inline so that Element
        can override it with an inline. This is the same technique we use for
        firstChild and lastChild.
        (WebCore::Node::virtualHasTagName): This is the private virtual that Element
        overrides.

        * dom/Text.cpp:
        (WebCore::Text::splitText): Clean up by using a RefPtr here instead of a
        PassRefPtr.

        * html/HTMLTokenizer.cpp:
        (WebCore::HTMLTokenizer::parseSpecial): Use the new advancePastNonNewline(),
        which is more efficient in cases where we know the character is not a newline
        and hence we don't have to update the line number.
        (WebCore::HTMLTokenizer::parseComment): Ditto.
        (WebCore::HTMLTokenizer::parseServer): Ditto.
        (WebCore::HTMLTokenizer::parseProcessingInstruction): Ditto.
        (WebCore::HTMLTokenizer::parseText): Ditto.
        (WebCore::HTMLTokenizer::parseEntity): Ditto.
        (WebCore::HTMLTokenizer::parseTag): Ditto. Also streamline the QuotedValue case
        so there's one less branch taken for non-punctuation characters since this
        code path is *so* hot.
        (WebCore::HTMLTokenizer::write): More of the same.

        * loader/Cache.cpp:
        (WebCore::Cache::lruListFor): Use Vector::grow instead of resize.

        * loader/DocumentLoader.cpp:
        (WebCore::canonicalizedTitle): Use StringBuffer instead of Vector<UChar>.

        * loader/TextResourceDecoder.cpp:
        (WebCore::TextResourceDecoder::checkForCSSCharset): Use Vector::grow instead of resize.
        (WebCore::TextResourceDecoder::checkForHeadCharset): Ditto.
        (WebCore::TextResourceDecoder::decode): Use Vector::grow and shrink instead of resize.
        (WebCore::TextResourceDecoder::flush): Use Vector::shrink instead of resize.

        * platform/KURL.cpp:
        (WebCore::KURL::decode_string): Use Vector::grow instead of resize.

        * platform/SharedBuffer.cpp:
        (WebCore::SharedBuffer::clear): Use Vector::shrink instead of resize.

        * platform/graphics/BitmapImage.cpp:
        (WebCore::BitmapImage::cacheFrame): Use Vector::grow instead of resize.

        * platform/network/FormData.cpp:
        (WebCore::FormData::appendData): Use Vector::grow instead of resize.
        (WebCore::FormData::flatten): Ditto.

        * platform/text/AtomicString.cpp:
        (WebCore::CStringTranslator::translate): Use a new StringImpl constructor made just
        for use by AtomicString. Avoids setting fields twice, and also preserves reference
        count behavior (which I changed for the other constructors, since they're entirely
        private and used only inside the class).
        (WebCore::UCharBufferTranslator::translate): Ditto.

        * platform/text/Base64.cpp:
        (WebCore::base64Encode): Use Vector::grow instead of resize.
        (WebCore::base64Decode): Use Vector::grow and shrink instead of resize.

        * platform/text/PlatformString.h:
        (WebCore::String::adopt): Added an overload for the new StringBuffer class. Also
        made both versions inline.

        * platform/text/SegmentedString.h:
        (WebCore::SegmentedString::advancePastNewline): Added. One less branch for case
        where the character is known to be a newline.
        (WebCore::SegmentedString::advancePastNonNewline): Added. Less code for case where
        the character is known not to be a newline.

        * platform/text/String.cpp:
        (WebCore::String::append): Use StringBuffer instead of Vector<UChar>.
        (WebCore::String::insert): Ditto.
        (WebCore::String::truncate): Ditto.
        (WebCore::String::remove): Ditto.
        (WebCore::String::format): Use Vector::grow instead of resize.

        * platform/text/StringImpl.cpp:
        (WebCore::StringImpl::StringImpl): Changed constructors to start with a refCount
        of 1 instead of 0, and made them all inline. Eliminates the WithOneRef constructor
        since they all behave this way now. The only exceptions are the constructors for
        AtomicString, which retain the old behavior.
        (WebCore::StringImpl::empty): Simplified, since we no longer need to use the
        special WithOneRef constructor.
        (WebCore::StringImpl::toCoordsArray): Use StringBuffer instead of Vector<UChar>.
        (WebCore::StringImpl::lower): Ditto.
        (WebCore::StringImpl::upper): Ditto.
        (WebCore::StringImpl::secure): Ditto.
        (WebCore::StringImpl::foldCase): Ditto.
        (WebCore::StringImpl::simplifyWhiteSpace): Ditto. Also change to use Vector::shrink
        instead of resize (since half of the function uses Vector<UChar>).
        (WebCore::StringImpl::capitalize): Use StringBuffer instead of Vector<UChar>.
        (WebCore::StringImpl::replace): Ditto.
        (WebCore::StringImpl::ascii): Streamlined a bit.
        (WebCore::StringImpl::createStrippingNullCharacters): Use StringBuffer insetad of
        Vector<UChar>. Took out checks for null characters and 0 length that aren't needed.
        Coded the check for null characters in a slightly more efficient way. Since this
        is so hot, didn't call adopt at all, putting the code right in here, including
        the call to the StringImpl constructor and adoptRef (for the fast case).
        (WebCore::StringImpl::adopt): Added a version for the new StringBuffer class.
        Removed the attempt to resize the buffer at the time we adopt based on measuring
        actual use and realizing that it's just a character here or there and not worth
        a call to fastRealloc. Changed to use adoptRef since the constructor now starts
        with a refCount of 1.
        (WebCore::StringImpl::create): Changed to use adoptRef since the constructor now
        starts with a refCount of 1.
        (WebCore::StringImpl::createWithTerminatingNullCharacter): Ditto.
        (WebCore::StringImpl::copy): Ditto. Also made non-inline since the constructor
        itself is now inline.

        * platform/text/StringImpl.h: Added a StringBuffer class that's useful for
        putting characters into a buffer before creating an immutable string. Not good
        at resizing the way Vector<UChar> is, so only useful for things that rarely need
        to be resized. Added a new AdoptBuffer constructor and empty constructor, but
        made all constructors private so they can be inlined and only used inside the
        StringImpl class. Added two new constructors for AtomicString. Made copy()
        no longer inline. Changed the type of the [] operator to unsigned instead of
        int and added an assertion. Made the hash functions inline.

        * platform/text/TextCodecICU.cpp:
        (WebCore::TextCodecICU::encode): Use Vector::grow instead of resize.

        * platform/text/TextCodecLatin1.cpp:
        (WebCore::TextCodecLatin1::decode): Use StringBuffer instead of Vector<UChar>.
        (WebCore::encodeComplexWindowsLatin1): Use Vector::grow instead of resize.

        * platform/text/TextCodecUTF16.cpp:
        (WebCore::TextCodecUTF16::decode): Use StringBuffer instead of Vector<UChar>.

        * platform/text/TextCodecUserDefined.cpp:
        (WebCore::TextCodecUserDefined::decode): Use StringBuffer instead of Vector<UChar>.
        (WebCore::encodeComplexUserDefined): Use Vector::grow instead of resize.

        * platform/text/TextEncoding.cpp:
        (WebCore::TextEncoding::encode): Use Vector::grow instead of resize.

        * platform/text/TextStream.cpp:
        (WebCore::TextStream::operator<<): Use Vector::grow instead of resize.

        * platform/text/mac/TextCodecMac.cpp:
        (WebCore::TextCodecMac::encode): Use Vector::grow instead of resize.

        * rendering/AutoTableLayout.cpp:
        (WebCore::AutoTableLayout::insertSpanCell): Use Vector::grow instead of resize.

        * rendering/RenderFrameSet.h:
        (WebCore::FrameEdgeInfo::FrameEdgeInfo): Allocate vectors with the correct initial
        size instead of calling resize on them after allocating empty.

        * rendering/RenderListMarker.cpp:
        (WebCore::RenderListMarker::paint): Use Vector::grow instead of resize.

        * rendering/RenderStyle.cpp: Removed CursorList::operator==.
        * rendering/RenderStyle.h:
        (WebCore::CursorList::operator==): Implemented using the Vector ==.
        (WebCore::CursorList::operator!=): Ditto.

        * rendering/RenderTable.cpp:
        (WebCore::RenderTable::splitColumn): Use Vector::grow instead of resize.
        (WebCore::RenderTable::appendColumn): Ditto.

        * rendering/RenderTableSection.cpp:
        (WebCore::RenderTableSection::ensureRows): Use Vector::grow instead of resize.

        * rendering/bidi.cpp:
        (WebCore::addMidpoint): Use Vector::grow instead of resize.

        * xml/XPathNodeSet.h:
        (WebCore::XPath::NodeSet::clear): Use Vector::shrink instead of resize.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@29470 268f45cc-cd09-0410-ab3c-d52691b4dbfc