Use StringView for String::append and ::insert.

Use StringView for String::append and ::insert.

This avoids allocating temporary strings when calling this method with a literal
string. I also simplified the code by merging the code paths.

Since StringAppend can't implicitly convert to StringView we can no longer write:
string.append(stringA + stringB) or string.append(stringA + "foo") since the
result of the + operator (a StringAppend object) is not allowed anymore. Doing
this actually caught a bunch of callers which were allocating temporary strings
trying to build up a bigger string and should be using StringBuilder instead. For
example extractWebGLContextCreationError was allocating a huge number of
temporary strings.

BUG=615174
Committed: https://crrev.com/f10ca9328c07c6bddfe281336072d5650a533dfc
Cr-Commit-Position: refs/heads/master@{#411285}

[esprehn, 2016-08-11 00:53:01]

Description was changed from

==========
Use StringView for String::append and ::insert.

BUG=
==========

to

==========
Use StringView for String::append and ::insert.

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

[esprehn, 2016-08-11 00:53:21]

Description was changed from

==========
Use StringView for String::append and ::insert.

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

to

==========
Use StringView for String::append and ::insert.

BUG=
==========

[esprehn, 2016-08-11 00:53:34]

Description was changed from

==========
Use StringView for String::append and ::insert.

BUG=
==========

to

==========
Use StringView for String::append and ::insert.

BUG=615174
==========

[esprehn, 2016-08-11 00:55:02]

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

[commit-bot: I haz the power, 2016-08-11 00:56:02]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-11 01:14:23]

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

[commit-bot: I haz the power, 2016-08-11 01:14:24]

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

[esprehn, 2016-08-11 02:23:36]

Description was changed from

==========
Use StringView for String::append and ::insert.

BUG=615174
==========

to

==========
Use StringView for String::append and ::insert.

BUG=615174
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

[esprehn, 2016-08-11 02:23:51]

Description was changed from

==========
Use StringView for String::append and ::insert.

BUG=615174
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

to

==========
Use StringView for String::append and ::insert.

BUG=615174
==========

[esprehn, 2016-08-11 02:27:12]

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

[commit-bot: I haz the power, 2016-08-11 02:27:49]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[esprehn, 2016-08-11 05:24:44]

esprehn@chromium.org changed reviewers:
+ haraken@chromium.org, yutak@chromium.org

[haraken, 2016-08-11 05:28:43]

LGTM


Would it make sense to rename String::append to something like
String::appendSlow to encourage people to use StringBuilder instead?

[esprehn, 2016-08-11 05:29:38]

Description was changed from

==========
Use StringView for String::append and ::insert.

BUG=615174
==========

to

==========
Use StringView for String::append and ::insert.

This avoids allocating temporary strings when calling this method with a literal
string. I also simplified the code by merging the code paths.

Since StringAppend can't implicitly convert to StringView we can no longer
write:
string.append(stringA + stringB) or string.append(stringA + "foo") since the
result of the + operator (a StringAppend object) is not allowed anymore. Doing
this actually caught a bunch of callers which were allocating temporary strings
trying to build up a bigger string and should be using StringBuilder instead.
For
example extractWebGLContextCreationError was allocating a huge number of
temporary strings.

BUG=615174
==========

[esprehn, 2016-08-11 05:30:54]

On 2016/08/11 at 05:28:43, haraken wrote:
> LGTM
> 
> 
> Would it make sense to rename String::append to something like
String::appendSlow to encourage people to use StringBuilder instead?

Possibly yeah, append() or operator+ is faster (avoids the copy in
StringBuilder::toString()) when you're only appending one thing, but it gets
misused so much maybe it's not worth it.

[esprehn, 2016-08-11 05:31:04]

The CQ bit was unchecked by esprehn@chromium.org

[esprehn, 2016-08-11 05:31:06]

The CQ bit was checked by esprehn@chromium.org

[commit-bot: I haz the power, 2016-08-11 05:31:21]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-11 07:43:27]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-08-11 07:46:04]

Description was changed from

==========
Use StringView for String::append and ::insert.

This avoids allocating temporary strings when calling this method with a literal
string. I also simplified the code by merging the code paths.

Since StringAppend can't implicitly convert to StringView we can no longer
write:
string.append(stringA + stringB) or string.append(stringA + "foo") since the
result of the + operator (a StringAppend object) is not allowed anymore. Doing
this actually caught a bunch of callers which were allocating temporary strings
trying to build up a bigger string and should be using StringBuilder instead.
For
example extractWebGLContextCreationError was allocating a huge number of
temporary strings.

BUG=615174
==========

to

==========
Use StringView for String::append and ::insert.

This avoids allocating temporary strings when calling this method with a literal
string. I also simplified the code by merging the code paths.

Since StringAppend can't implicitly convert to StringView we can no longer
write:
string.append(stringA + stringB) or string.append(stringA + "foo") since the
result of the + operator (a StringAppend object) is not allowed anymore. Doing
this actually caught a bunch of callers which were allocating temporary strings
trying to build up a bigger string and should be using StringBuilder instead.
For
example extractWebGLContextCreationError was allocating a huge number of
temporary strings.

BUG=615174

Committed: https://crrev.com/f10ca9328c07c6bddfe281336072d5650a533dfc
Cr-Commit-Position: refs/heads/master@{#411285}
==========

[commit-bot: I haz the power, 2016-08-11 07:46:05]

Patchset 2 (id:??) landed as
https://crrev.com/f10ca9328c07c6bddfe281336072d5650a533dfc
Cr-Commit-Position: refs/heads/master@{#411285}