Measure the usage of prefixed WebKitShadowRoot constructor.

BUG=242153
R=haraken@chromium.org

Review URL: https://chromiumcodereview.appspot.com/22393003

git-svn-id: svn://svn.chromium.org/blink/trunk@155760 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a pass-through gyp file for copy_TestNetscapePlugIn target.

This change is necessary to migrate Chromium from DumpRenderTree to public/.

After this lands and rolls on Chromium, the entries of
DumpRenderTree.gyp:copy_TestNetscapePlugIn will be changing to reference
blink_test_plugin.gyp instead.

R=abarth@chromium.org

Review URL: https://chromiumcodereview.appspot.com/22482007

git-svn-id: svn://svn.chromium.org/blink/trunk@155761 bbb929c8-8fbe-4397-9dbb-9b2b20218538