[CSS3 Backgrounds and Borders] Remove CSS3_BACKGROUND feature flag.
https://bugs.webkit.org/show_bug.cgi?id=104539

Reviewed by Antonio Gomes.

.:

As discussed on webkit-dev it is not needed to keep this feature flag
as support for <position> type is a small feature that is already
implemented by three other UAs. It was useful while landing this
feature as partial bits were landed one after one.

* Source/cmake/OptionsEfl.cmake:
* Source/cmake/WebKitFeatures.cmake:
* Source/cmakeconfig.h.cmake:
* configure.ac:

Source/JavaScriptCore:

As discussed on webkit-dev it is not needed to keep this feature flag
as support for <position> type is a small feature that is already
implemented by three other UAs. It was useful while landing this
feature as partial bits were landed one after one.

* Configurations/FeatureDefines.xcconfig:

Source/WebCore:

As discussed on webkit-dev it is not needed to keep this feature flag
as support for <position> type is a small feature that is already
implemented by three other UAs. It was useful while landing this
feature as partial bits were landed one after one.

No new tests : the feature is covered by various tests and it is already enabled in many ports.

* Configurations/FeatureDefines.xcconfig:
* GNUmakefile.am:
* GNUmakefile.features.am:
* css/CSSParser.cpp:
(WebCore::CSSParser::parseFillPosition):
(WebCore::CSSParser::parseFillProperty):
* css/CSSParser.h:
* css/CSSToStyleMap.cpp:
(WebCore::CSSToStyleMap::mapFillXPosition):
(WebCore::CSSToStyleMap::mapFillYPosition):
* rendering/style/FillLayer.cpp:
(SameSizeAsFillLayer):
(WebCore::FillLayer::FillLayer):
(WebCore::FillLayer::operator=):
(WebCore::FillLayer::operator==):
(WebCore::FillLayer::fillUnsetProperties):
* rendering/style/FillLayer.h:
(WebCore::FillLayer::backgroundXOrigin):
(WebCore::FillLayer::backgroundYOrigin):
(WebCore::FillLayer::isBackgroundOriginSet):
(WebCore::FillLayer::clearXPosition):
(WebCore::FillLayer::clearYPosition):
(FillLayer):

Source/WebKit/chromium:

As discussed on webkit-dev it is not needed to keep this feature flag
as support for <position> type is a small feature that is already
implemented by three other UAs. It was useful while landing this
feature as partial bits were landed one after one.

* features.gypi:

Source/WebKit/mac:

As discussed on webkit-dev it is not needed to keep this feature flag
as support for <position> type is a small feature that is already
implemented by three other UAs. It was useful while landing this
feature as partial bits were landed one after one.

* Configurations/FeatureDefines.xcconfig:

Source/WebKit2:

As discussed on webkit-dev it is not needed to keep this feature flag
as support for <position> type is a small feature that is already
implemented by three other UAs. It was useful while landing this
feature as partial bits were landed one after one.

* Configurations/FeatureDefines.xcconfig:

Tools:

As discussed on webkit-dev it is not needed to keep this feature flag
as support for <position> type is a small feature that is already
implemented by three other UAs. It was useful while landing this
feature as partial bits were landed one after one.

* Scripts/webkitperl/FeatureList.pm:
* qmake/mkspecs/features/features.pri:

WebKitLibraries:

As discussed on webkit-dev it is not needed to keep this feature flag
as support for <position> type is a small feature that is already
implemented by three other UAs. It was useful while landing this
feature as partial bits were landed one after one.

* win/tools/vsprops/FeatureDefines.vsprops:
* win/tools/vsprops/FeatureDefinesCairo.vsprops:

LayoutTests:

Unskip the related CSS3 <position> type tests for background-position
as now the feature is enabled by default.

* platform/win/TestExpectations:
* platform/wincairo/TestExpectations:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@137166 268f45cc-cd09-0410-ab3c-d52691b4dbfc
cr-win build fix after r137161.

Unreviewed.

* platform/graphics/MediaPlayer.h: Replace forward-decl of
InbandTextTrackPrivate with #include as the definition is required.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@137167 268f45cc-cd09-0410-ab3c-d52691b4dbfc