DEPS.xwalk: Roll blink-crosswalk ed2bae8 -> a6caf4f

a6caf4f Merge pull request #29 from elvin-nnov/master
a2011aa The Chrome DevTools protocol part of the XDK in-depth allocation tracker
b44bae8 Merge pull request #27 from eleskine/blinkprf-102
d7c846a Chromium CPU profiler: source line support
f930e9d Merge pull request #26 from rakuco/revert-webgl-opt
2799075 Revert "[Backport Patch] Use glDiscardFramebuffer instead of glClear"
ca0b98c Merge pull request #25 from hmin/webgl-opt
90a30f1 [Backport Patch] Use glDiscardFramebuffer instead of glClear