Remove 'read_only': 1 from most .isolate files.

Remove 'read_only': 1 from most .isolate files.

These were mostly due to blind copy-paste. read_only:1 is the default so there's
no point in specifying it.

As per crbug.com/342913, only unit_tests has issue with running from read only
files.

R=jam@chromium.org
BUG=116251
Committed: https://crrev.com/94bc4db5e341fbda8ce8f2210c9fc6b056a82868
Cr-Commit-Position: refs/heads/master@{#339490}

[M-A Ruel, 2015-07-20 16:01:21]

Minor cleanup before starting to remove more stuff.

[M-A Ruel, 2015-07-20 16:01:28]

The CQ bit was checked by maruel@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-07-20 16:01:59]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1240303002/1

[commit-bot: I haz the power, 2015-07-20 17:26:36]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-20 17:26:36]

Dry run: Try jobs failed on following builders:
  linux_chromium_asan_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[jam, 2015-07-20 18:37:10]

lgtm

[M-A Ruel, 2015-07-20 19:09:30]

The CQ bit was checked by maruel@chromium.org

[commit-bot: I haz the power, 2015-07-20 19:11:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1240303002/1

[commit-bot: I haz the power, 2015-07-20 19:45:52]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-20 19:46:50]

Patchset 1 (id:??) landed as
https://crrev.com/94bc4db5e341fbda8ce8f2210c9fc6b056a82868
Cr-Commit-Position: refs/heads/master@{#339490}