https://bugs.webkit.org/show_bug.cgi?id=94888

Reviewed by Brady Eidson.

Source/WebCore:

Added functions for discerning if a plugin should be able to access its storage in its current origin.

Tests: http/tests/security/cross-origin-plugin-allowed.html
       http/tests/security/cross-origin-plugin.html

* WebCore.exp.in: Export FrameTree::top and SecurityOrigin::canAccessStorage
* page/SecurityOrigin.h: Added canAccessPluginStorage
(WebCore::SecurityOrigin::canAccessPluginStorage):

Source/WebKit2:

Plugins that are in a third-party context should be put into private browsing mode so their storage is temporary.

* WebProcess/Plugins/PluginView.cpp:
(WebKit::PluginView::isPrivateBrowsingEnabled): Put the plugin into private browsing mode if it is in a third-party context.
(WebKit::PluginView::privateBrowsingStateChanged): Make sure a plugin doesn't leave private browsing mode if it's in a third-party context.

LayoutTests:

Created tests for plugins in a third party and first party context when third-party blocking is on and off.

* http/tests/security/cross-origin-plugin-allowed-expected.txt: Added.
* http/tests/security/cross-origin-plugin-allowed.html: Added.
* http/tests/security/cross-origin-plugin-expected.txt: Added.
* http/tests/security/cross-origin-plugin-private-browsing-toggled-allowed-expected.txt: Added.
* http/tests/security/cross-origin-plugin-private-browsing-toggled-allowed.html: Added.
* http/tests/security/cross-origin-plugin-private-browsing-toggled-expected.txt: Added.
* http/tests/security/cross-origin-plugin-private-browsing-toggled.html: Added.
* http/tests/security/cross-origin-plugin.html: Added.
* http/tests/security/resources/cross-origin-iframe-for-plugin.html: Added.
* http/tests/security/resources/cross-origin-iframe-for-plugin-async.html: Added.
* platform/mac-wk2/http/tests/security/cross-origin-plugin-expected.txt: Added.
* platform/mac-wk2/http/tests/security/cross-origin-plugin-private-browsing-toggled-expected.txt: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@127513 268f45cc-cd09-0410-ab3c-d52691b4dbfc