https://bugs.webkit.org/show_bug.cgi?id=124210

Reviewed by Andreas Kling.

Creating an ImmutableArray of WebStrings is a common operation, so add a
helper function to ImmutableArray that does this from a Vector of Strings.

* Shared/ImmutableArray.cpp:
(WebKit::ImmutableArray::createStringArray):
* Shared/ImmutableArray.h:
* Shared/ImmutableDictionary.cpp:
(WebKit::ImmutableDictionary::keys):
* Shared/WebOpenPanelParameters.cpp:
(WebKit::WebOpenPanelParameters::acceptMIMETypes):
(WebKit::WebOpenPanelParameters::selectedFileNames):
* UIProcess/Plugins/WebPluginSiteDataManager.cpp:
(WebKit::WebPluginSiteDataManager::didGetSitesWithData):
* UIProcess/WebCookieManagerProxy.cpp:
(WebKit::WebCookieManagerProxy::didGetHostnamesWithCookies):
* UIProcess/WebMediaCacheManagerProxy.cpp:
(WebKit::WebMediaCacheManagerProxy::didGetHostnamesWithMediaCache):
* WebProcess/InjectedBundle/InjectedBundlePageLoaderClient.cpp:
(WebKit::InjectedBundlePageLoaderClient::featuresUsedInPage):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@159123 268f45cc-cd09-0410-ab3c-d52691b4dbfc