https://bugs.webkit.org/show_bug.cgi?id=98696

Reviewed by Tim Horton.

Expose a new setting maximumPlugInSnapshotAttempts that can
be set by testing scripts.

Tests: plugins/snapshotting/restart.html
       plugins/snapshotting/simple.html

* page/Settings.in:

Source/WebKit2: Allow PlugIn Snapshotting to be tested
https://bugs.webkit.org/show_bug.cgi?id=98696

Reviewed by Tim Horton.

Use the new maximumPlugInSnapshotAttempts setting rather than a hardcoded
value. At the same time, if this value is 0, then snapshot immediately
(don't wait to get a snapshot and test it).

* WebProcess/Plugins/PluginView.cpp:
(WebKit::PluginView::didInitializePlugin): Snapshot immediately if maximum attempts are 0.
(WebKit::PluginView::pluginSnapshotTimerFired): Use setting rather than file local variable.

LayoutTests: Allow PlugIn Snapshotting to be tested
https://bugs.webkit.org/show_bug.cgi?id=98696
<rdar://problem/12456731>

Reviewed by Tim Horton.

Two new simple tests for plugin snapshotting. One that makes
sure the plugin was snapshotted (looks for the RenderSnapshottedPlugin)
and one that restarts a snapshotted plugin by clicking.

Since this feature is currently only enabled in WebKit2, the tests
are skipped everywhere else.

* platform/chromium/TestExpectations: Skip plugins/snapshotting.
* platform/efl/TestExpectations: Ditto.
* platform/gtk/TestExpectations: Ditto.
* platform/mac-wk2/TestExpectations: Ditto.
* platform/mac-wk2/plugins/snapshotting/restart-expected.txt: Added.
* platform/mac-wk2/plugins/snapshotting/simple-expected.txt: Added.
* platform/mac/TestExpectations: Skip plugins/snapshotting.
* platform/qt/TestExpectations: Ditto.
* platform/win/TestExpectations: Ditto.
* plugins/snapshotting/restart.html: Added.
* plugins/snapshotting/simple.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@146250 268f45cc-cd09-0410-ab3c-d52691b4dbfc