Discard atlas after every MultiPictureDraw::draw

This is intended to prevent ghosting on tiled architectures.

This CL also defers creation of the atlas (and its texture) until it is actually needed.

Review URL: https://codereview.chromium.org/678403002
Use SkTypeface::getBounds() in bounding-box calculations.

This should produce tighter conservative bounding boxes for text than the
approximation code it replaces.

Recording performance is neutral on my desktop.  Playback performance
improves by up to 15% on text heavy pages, e.g.

  desk_pokemonwiki.skp_1 3.24ms -> 2.83ms  0.87x
        desk_baidu.skp_1 1.91ms -> 1.58ms  0.83x

Review URL: https://codereview.chromium.org/680363003
Revert of Discard atlas after every MultiPictureDraw::draw (patchset #4 id:60001 of https://codereview.chromium.org/678403002/)

Reason for revert:
Breaking bots

Original issue's description:
> Discard atlas after every MultiPictureDraw::draw
>
> This is intended to prevent ghosting on tiled architectures.
>
> This CL also defers creation of the atlas (and its texture) until it is actually needed.
>
> Committed: https://skia.googlesource.com/skia/+/6d5b5455743414ddb11d2b8c1fe9d7959f2b853d

TBR=bsalomon@google.com
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/687233002
pagesets are still crashing in RecreateSKPs bot, try adding waits to most pagesets

BUG=skia:3049
NOTRY=true
TBR=borenet

Review URL: https://codereview.chromium.org/682573004
Revert of Use SkTypeface::getBounds() in bounding-box calculations. (patchset #3 id:40001 of https://codereview.chromium.org/680363003/)

Reason for revert:
http://build.chromium.org/p/client.skia/builders/Test-Win7-ShuttleA-HD2000-x86-Debug/builds/97/steps/nanobench/logs/stdio

Original issue's description:
> Use SkTypeface::getBounds() in bounding-box calculations.
>
> This should produce tighter conservative bounding boxes for text than the
> approximation code it replaces.
>
> Recording performance is neutral on my desktop.  Playback performance
> improves by up to 15% on text heavy pages, e.g.
>
>   desk_pokemonwiki.skp_1 3.24ms -> 2.83ms  0.87x
>         desk_baidu.skp_1 1.91ms -> 1.58ms  0.83x
>
> Committed: https://skia.googlesource.com/skia/+/bf8dc343df4fbdcb8af546eb68b640e011a33489

TBR=reed@google.com,mtklein@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/685173002
Update adb on linux to 1.0.32

Review URL: https://codereview.chromium.org/684203002
clear stencil clip on draw target

TBR=
BUG=skia:

Review URL: https://codereview.chromium.org/683673002
SkTaskGroup::add(fn, arg)

NOTREECHECKS=true

BUG=skia:

Review URL: https://codereview.chromium.org/687953003
Increase wait times for androidpolice and nytimes
delete webtry from main skia repo; it's been moved to buildbots

BUG=skia:

Review URL: https://codereview.chromium.org/688713002