Add navigator.registerProtocolHandler behind a flag.

Add navigator.registerProtocolHandler behind a flag.
https://bugs.webkit.org/show_bug.cgi?id=52609

Patch by James Kozianski <koz@chromium.org> on 2011-02-03
Reviewed by Dimitri Glazkov.

Source/JavaScriptCore:

* Configurations/FeatureDefines.xcconfig:

Source/WebCore:

This method is described in the HTML5 specification here,
http://dev.w3.org/html5/spec/Overview.html#dom-navigator-registerprotocolhandler

This change is largely cribbed from B. Green's 29651 patches. It is
behind a flag so as not to break JS feature detection.

New layout test fast/dom/registerProtocolHandler.html.

* Configurations/FeatureDefines.xcconfig:
* loader/EmptyClients.h:
(WebCore::EmptyChromeClient::registerProtocolHandler):
* page/Chrome.cpp:
(WebCore::Chrome::registerProtocolHandler):
* page/Chrome.h:
* page/ChromeClient.h:
* page/Navigator.cpp:
(WebCore::verifyCustomHandlerURL):
(WebCore::verifyProtocolHandlerScheme):
(WebCore::Navigator::registerProtocolHandler):
* page/Navigator.h:
* page/Navigator.idl:

Source/WebKit/chromium:

* features.gypi:
* public/WebViewClient.h:
* src/ChromeClientImpl.cpp:
(WebKit::ChromeClientImpl::registerProtocolHandler):
* src/ChromeClientImpl.h:

Source/WebKit/mac:

* Configurations/FeatureDefines.xcconfig:

Source/WebKit2:

* Configurations/FeatureDefines.xcconfig:

Tools:

* Scripts/build-webkit:

WebKitLibraries:

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

LayoutTests:

* fast/dom/register-protocol-handler-expected.txt: Added.
* fast/dom/register-protocol-handler.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@77607 268f45cc-cd09-0410-ab3c-d52691b4dbfc