https://bugs.webkit.org/show_bug.cgi?id=123932

Reviewed by Sam Weinig.

Source/JavaScriptCore:

Add feature define ENABLE_LETTERPRESS disabled by default. We only enable
letterpress on iOS.

* Configurations/FeatureDefines.xcconfig:

Source/WebCore:

Test: platform/iphone-simulator/iphone/getComputedStyle-text-decoration-letterpress.html

* Configurations/FeatureDefines.xcconfig: Add feature define ENABLE_LETTERPRESS disabled
by default. We only enable letterpress on iOS.
* css/CSSComputedStyleDeclaration.cpp:
(WebCore::renderTextDecorationFlagsToCSSValue): Add support for CSS value -webkit-letterpress.
* css/CSSParser.cpp:
(WebCore::CSSParser::parseTextDecoration): Ditto.
* css/CSSPrimitiveValueMappings.h:
(WebCore::CSSPrimitiveValue::operator TextDecoration): Ditto.
* css/CSSValueKeywords.in: Added CSS value -webkit-letterpress.
* platform/graphics/GraphicsContext.h:
* platform/graphics/mac/FontMac.mm:
(WebCore::fillVectorWithHorizontalGlyphPositions): Added.
(WebCore::shouldUseLetterpressEffect): Added.
(WebCore::showLetterpressedGlyphsWithAdvances): Added.
(WebCore::showGlyphsWithAdvances): Modified to call showLetterpressedGlyphsWithAdvances()
to show a letterpressed glyph. I also included additional iOS-specific changes.
(WebCore::Font::drawGlyphs):
* rendering/TextPaintStyle.cpp:
(WebCore::TextPaintStyle::TextPaintStyle):
(WebCore::computeTextPaintStyle): Modified to compute letterpress effect style.
(WebCore::updateGraphicsContext): Modified to apply/unapply letterpress effect drawing mode.
* rendering/TextPaintStyle.h:
* rendering/style/RenderStyleConstants.h:

Source/WebKit/mac:

Add feature define ENABLE_LETTERPRESS disabled by default. We only enable
letterpress on iOS.

* Configurations/FeatureDefines.xcconfig:

Source/WebKit2:

Add feature define ENABLE_LETTERPRESS disabled by default. We only enable
letterpress on iOS.

* Configurations/FeatureDefines.xcconfig:

Source/WTF:

Add feature define ENABLE_LETTERPRESS disabled by default. We only enable
letterpress on iOS.

* wtf/FeatureDefines.h:

LayoutTests:

* platform/iphone-simulator/iphone/getComputedStyle-text-decoration-letterpress-expected.txt: Added.
* platform/iphone-simulator/iphone/getComputedStyle-text-decoration-letterpress.html: Added.
* platform/iphone-simulator/iphone/resources/getComputedStyle-text-decoration-letterpress.js: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@158803 268f45cc-cd09-0410-ab3c-d52691b4dbfc