Avoid string allocation when parsing CSSPrimitiveValue::UnitType

Avoid string allocation when parsing CSSPrimitiveValue::UnitType

Currently the CSSPrimitiveValue::fromName function, which parses strings
to unit types, takes a String argument. This means that the CSS parser
needs to allocate a String (since it would only otherwise have a
CSSParserString). This patch avoids this allocation using a generated
switch-statement trie instead.

Generated file: http://paste.ubuntu.com/16652358/

This improves performance of the inline-transform-benchmark test from
https://bugs.chromium.org/p/chromium/issues/detail?id=605792, reducing
the time spent in CSSParserImpl::parseValue by 10%.

Patch originally written by meade@chromium.org:
https://codereview.chromium.org/1938343002

BUG=605792, 606695
Committed: https://crrev.com/a753d727f2d92f67b594312a6710c931b37a49b3
Cr-Commit-Position: refs/heads/master@{#395849}

[Timothy Loh, 2016-05-24 07:21:12]

timloh@chromium.org changed reviewers:
+ alancutter@chromium.org

[Timothy Loh, 2016-05-24 07:21:12]

Uploading this since meade@ is OOO (although since 52 just branched I guess we
could've just waited). This is the last patch at
https://codereview.chromium.org/1938343002 rebased and with small changes.

[Timothy Loh, 2016-05-24 08:59:05]

Description was changed from

==========
Avoid string allocation when parsing CSSPrimitiveValue::UnitType

Currently the CSSPrimitiveValue::fromName function, which parses strings
to unit types, takes a String argument. This means that the CSS parser
needs to allocate a String (since it would only otherwise have a
CSSParserString). This patch avoids this allocation using a generated
switch-statement trie instead.

This improves performance of the inline-transform-benchmark test from
https://bugs.chromium.org/p/chromium/issues/detail?id=605792, reducing
the time spent in CSSParserImpl::parseValue by 10%.

Patch originally written by meade@chromium.org:
https://codereview.chromium.org/1938343002

BUG=605792,606695
==========

to

==========
Avoid string allocation when parsing CSSPrimitiveValue::UnitType

Currently the CSSPrimitiveValue::fromName function, which parses strings
to unit types, takes a String argument. This means that the CSS parser
needs to allocate a String (since it would only otherwise have a
CSSParserString). This patch avoids this allocation using a generated
switch-statement trie instead.

Generated file: http://paste.ubuntu.com/16652358/

This improves performance of the inline-transform-benchmark test from
https://bugs.chromium.org/p/chromium/issues/detail?id=605792, reducing
the time spent in CSSParserImpl::parseValue by 10%.

Patch originally written by meade@chromium.org:
https://codereview.chromium.org/1938343002

BUG=605792,606695
==========

[alancutter (OOO until 2018), 2016-05-25 07:07:11]

lgtm.

[Timothy Loh, 2016-05-25 07:17:20]

The CQ bit was checked by timloh@chromium.org

[commit-bot: I haz the power, 2016-05-25 07:17:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2002383002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2002383002/20001

[commit-bot: I haz the power, 2016-05-25 07:21:26]

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

[commit-bot: I haz the power, 2016-05-25 07:21:27]

Try jobs failed on following builders:
  ios-device on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/builds...)
  win8_chromium_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_ng/...)

[Timothy Loh, 2016-05-25 07:45:38]

The CQ bit was checked by timloh@chromium.org

[Timothy Loh, 2016-05-25 07:45:38]

The patchset sent to the CQ was uploaded after l-g-t-m from
alancutter@chromium.org
Link to the patchset: https://codereview.chromium.org/2002383002/#ps40001
(title: "rebase")

[commit-bot: I haz the power, 2016-05-25 07:45:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2002383002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2002383002/40001

[commit-bot: I haz the power, 2016-05-25 10:02:48]

Description was changed from

==========
Avoid string allocation when parsing CSSPrimitiveValue::UnitType

Currently the CSSPrimitiveValue::fromName function, which parses strings
to unit types, takes a String argument. This means that the CSS parser
needs to allocate a String (since it would only otherwise have a
CSSParserString). This patch avoids this allocation using a generated
switch-statement trie instead.

Generated file: http://paste.ubuntu.com/16652358/

This improves performance of the inline-transform-benchmark test from
https://bugs.chromium.org/p/chromium/issues/detail?id=605792, reducing
the time spent in CSSParserImpl::parseValue by 10%.

Patch originally written by meade@chromium.org:
https://codereview.chromium.org/1938343002

BUG=605792,606695
==========

to

==========
Avoid string allocation when parsing CSSPrimitiveValue::UnitType

Currently the CSSPrimitiveValue::fromName function, which parses strings
to unit types, takes a String argument. This means that the CSS parser
needs to allocate a String (since it would only otherwise have a
CSSParserString). This patch avoids this allocation using a generated
switch-statement trie instead.

Generated file: http://paste.ubuntu.com/16652358/

This improves performance of the inline-transform-benchmark test from
https://bugs.chromium.org/p/chromium/issues/detail?id=605792, reducing
the time spent in CSSParserImpl::parseValue by 10%.

Patch originally written by meade@chromium.org:
https://codereview.chromium.org/1938343002

BUG=605792,606695
==========

[commit-bot: I haz the power, 2016-05-25 10:02:49]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-05-25 10:05:02]

Description was changed from

==========
Avoid string allocation when parsing CSSPrimitiveValue::UnitType

Currently the CSSPrimitiveValue::fromName function, which parses strings
to unit types, takes a String argument. This means that the CSS parser
needs to allocate a String (since it would only otherwise have a
CSSParserString). This patch avoids this allocation using a generated
switch-statement trie instead.

Generated file: http://paste.ubuntu.com/16652358/

This improves performance of the inline-transform-benchmark test from
https://bugs.chromium.org/p/chromium/issues/detail?id=605792, reducing
the time spent in CSSParserImpl::parseValue by 10%.

Patch originally written by meade@chromium.org:
https://codereview.chromium.org/1938343002

BUG=605792,606695
==========

to

==========
Avoid string allocation when parsing CSSPrimitiveValue::UnitType

Currently the CSSPrimitiveValue::fromName function, which parses strings
to unit types, takes a String argument. This means that the CSS parser
needs to allocate a String (since it would only otherwise have a
CSSParserString). This patch avoids this allocation using a generated
switch-statement trie instead.

Generated file: http://paste.ubuntu.com/16652358/

This improves performance of the inline-transform-benchmark test from
https://bugs.chromium.org/p/chromium/issues/detail?id=605792, reducing
the time spent in CSSParserImpl::parseValue by 10%.

Patch originally written by meade@chromium.org:
https://codereview.chromium.org/1938343002

BUG=605792,606695

Committed: https://crrev.com/a753d727f2d92f67b594312a6710c931b37a49b3
Cr-Commit-Position: refs/heads/master@{#395849}
==========

[commit-bot: I haz the power, 2016-05-25 10:05:03]

Patchset 3 (id:??) landed as
https://crrev.com/a753d727f2d92f67b594312a6710c931b37a49b3
Cr-Commit-Position: refs/heads/master@{#395849}