DevTools: Fix error: Node with unknown id undefined at index
DevTools: Fix error: Node with unknown id undefined at index

There's an extra timestamp was added to the timestamps array so we can
easily calculate deltas from the timestamps.
However that happens before it performs CPUProfileDataModel._sortSamples
which once timestamps happen to be not sorted starts reordering both
timestamps and samples arrays. That sometimes causes last timestamp
item to be moved along with a missing value in samples array
somewhere in the middle effectively adding an extra 'undefined' item
to the samples array.

BUG=850892

Change-Id: Ie0706dadb031803698e3f8700bd4a08523201bef
Reviewed-on: https://chromium-review.googlesource.com/1093441
Commit-Queue: Alexei Filippov <52e51c43e283548b762e3c9dd9a4600768db9fb4@chromium.org>
Reviewed-by: Dmitry Gozman <0ca14b32cbb359a30ac562af27dd84cc2813eacb@chromium.org>
Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#565804}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: fe5b5f754ea2c92750a8f9eb81118f3cfc96beee
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