REGRESSION(r170743): [GTK] [EFL] Build broken.
https://bugs.webkit.org/show_bug.cgi?id=134585

Reviewed by Philippe Normand.

Add ENABLE(PRIMARY_SNAPSHOTTED_PLUGIN_HEURISTIC) guards where needed.

* WebProcess/Plugins/PluginView.cpp:
(WebKit::PluginView::initializePlugin):
* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::createPlugin):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@170747 268f45cc-cd09-0410-ab3c-d52691b4dbfc
REGRESSION(r170676): [GTK] UI process crashes when the Web Process crashes
https://bugs.webkit.org/show_bug.cgi?id=134541

Reviewed by Gyuyoung Kim.

It happens when attaching a new web process, because it tries to
encode a null SessionState.

* UIProcess/LegacySessionStateCodingNone.cpp:
(WebKit::encodeLegacySessionState): Return an empty API::Data
object instead of nullptr.
(WebKit::encodeLegacySessionHistoryEntryData): Ditto.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@170748 268f45cc-cd09-0410-ab3c-d52691b4dbfc