customtabs: Don't create an extra child process when one is already there.

customtabs: Don't create an extra child process when one is already there.

When a CustomTabActivity is created, the normal initialization sequence
in AsyncInitializationActivity allocates a new child connection. This
asks Android to start a new isolated process. When a spare renderer or a
prerender is used, this is useless and wasteful. Even though this mostly
does not happen on the main thread, child process binding usually takes
>150ms on Android.
Removing this overhead saves memory (a few MB of PSS) and CPU time, and
should speed up Custom Tabs startup, especially on low-end devices.

BUG=607560
Committed: https://crrev.com/e9391e898bef5109a3b41bb2cf79548c62668e4e
Cr-Commit-Position: refs/heads/master@{#401609}

[Benoit L, 2016-06-22 14:23:13]

lizeb@chromium.org changed reviewers:
+ yusufo@chromium.org

[Yusuf, 2016-06-23 14:35:15]

lgtm

[Benoit L, 2016-06-23 14:39:12]

lizeb@chromium.org changed reviewers:
+ tedchoc@chromium.org

[Benoit L, 2016-06-23 14:39:13]

Hi tedchoc@,

This is a change to prevent us from needlessly creating child processes, and as
my grandma said, "doing and undoing, it's still doing work."
It is expected to matter for >90% of custom tabs.

PTAL, thanks.

[Ted C, 2016-06-23 14:45:21]

lgtm

[Benoit L, 2016-06-23 14:46:03]

The CQ bit was checked by lizeb@chromium.org

[commit-bot: I haz the power, 2016-06-23 14:46:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2087043003/1

[commit-bot: I haz the power, 2016-06-23 15:20:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-23 15:22:52]

Description was changed from

==========
customtabs: Don't create an extra child process when one is already there.

When a CustomTabActivity is created, the normal initialization sequence
in AsyncInitializationActivity allocates a new child connection. This
asks Android to start a new isolated process. When a spare renderer or a
prerender is used, this is useless and wasteful. Even though this mostly
does not happen on the main thread, child process binding usually takes
>150ms on Android.
Removing this overhead saves memory (a few MB of PSS) and CPU time, and
should speed up Custom Tabs startup, especially on low-end devices.

BUG=607560
==========

to

==========
customtabs: Don't create an extra child process when one is already there.

When a CustomTabActivity is created, the normal initialization sequence
in AsyncInitializationActivity allocates a new child connection. This
asks Android to start a new isolated process. When a spare renderer or a
prerender is used, this is useless and wasteful. Even though this mostly
does not happen on the main thread, child process binding usually takes
>150ms on Android.
Removing this overhead saves memory (a few MB of PSS) and CPU time, and
should speed up Custom Tabs startup, especially on low-end devices.

BUG=607560

Committed: https://crrev.com/e9391e898bef5109a3b41bb2cf79548c62668e4e
Cr-Commit-Position: refs/heads/master@{#401609}
==========

[commit-bot: I haz the power, 2016-06-23 15:22:53]

Patchset 1 (id:??) landed as
https://crrev.com/e9391e898bef5109a3b41bb2cf79548c62668e4e
Cr-Commit-Position: refs/heads/master@{#401609}