Add perf tests for video element copies for Canvas/WebGL to catch performance improvements and regressions.

We have aleady perf tests that copy both WebGL and Canvas2D each other, but
don't have video perf tests. This CL fills up the vacancy.

720x576i-anamorphic.mov is copied from LayoutTests/media/content, because we
cannot reuse a resouces outside PerformanceTests/.
I choose 720x576i-anamorphic.mov among many videos because the frame of this
video is the biggest and this video is HW acceleratable on CrOS.

BUG=242244, 349871

Review URL: https://codereview.chromium.org/196413013

git-svn-id: svn://svn.chromium.org/blink/trunk@170364 bbb929c8-8fbe-4397-9dbb-9b2b20218538