https://bugs.webkit.org/show_bug.cgi?id=113503

Reviewed by Yury Semikhatsky.

Refactoring, covered by existing tests.

- rename HeapGraph to TimelineMemoryOverview;
- rename TimelineCategoryStrips to TimelineEventOvrview.

* inspector/front-end/TimelineOverviewPane.js:
(WebInspector.TimelineOverviewPane):
(WebInspector.TimelineOverviewPane.prototype.setMode):
(WebInspector.TimelineOverviewPane.prototype._setFrameMode):
(WebInspector.TimelineOverviewPane.prototype._onCategoryVisibilityChanged):
(WebInspector.TimelineOverviewPane.prototype._update):
(WebInspector.TimelineOverviewPane.prototype.setMinimumRecordDuration):
(WebInspector.TimelineMemoryOverview):
(WebInspector.TimelineEventOverview):
(WebInspector.TimelineEventOverview.prototype._renderBar):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147109 268f45cc-cd09-0410-ab3c-d52691b4dbfc