Web Inspector: [Canvas] do not store a dropped trace log in backend
https://bugs.webkit.org/show_bug.cgi?id=108600

Reviewed by Pavel Feldman.

Clear memory immediately on dropping current trace log instead of waiting for the next capture command.

* inspector/InjectedScriptCanvasModuleSource.js:
(.):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141884 268f45cc-cd09-0410-ab3c-d52691b4dbfc