Initialize properly availableHeight in computePercentageLogicalHeight

Initialize properly availableHeight in computePercentageLogicalHeight

In r648880 we introduced a regression because of the new implementation
of LayoutBox::computePercentageLogicalHeight() was wrongly initializing
as 0 the availableHeight variable.
We should just use -1 like the code was doing before that patch.

BUG=648880
TEST=fast/table/quirks-mode-percent-height.html

Committed: https://crrev.com/5b0f27ec040f501eb7af22ea017db9f4f0c902dd
Cr-Commit-Position: refs/heads/master@{#421145}

[Manuel Rego, 2016-09-26 19:35:47]

rego@igalia.com changed reviewers:
+ cbiesinger@chromium.org, eae@chromium.org, jfernandez@igalia.com,
svillar@igalia.com

[cbiesinger, 2016-09-26 20:44:36]

lgtm

[Manuel Rego, 2016-09-27 06:52:24]

The CQ bit was checked by rego@igalia.com

[commit-bot: I haz the power, 2016-09-27 06:52:34]

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, 2016-09-27 08:08:11]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-27 08:10:00]

Description was changed from

==========
Initialize properly availableHeight in computePercentageLogicalHeight

In r648880 we introduced a regression because of the new implementation
of LayoutBox::computePercentageLogicalHeight() was wrongly initializing
as 0 the availableHeight variable.
We should just use -1 like the code was doing before that patch.

BUG=648880
TEST=fast/table/quirks-mode-percent-height.html
==========

to

==========
Initialize properly availableHeight in computePercentageLogicalHeight

In r648880 we introduced a regression because of the new implementation
of LayoutBox::computePercentageLogicalHeight() was wrongly initializing
as 0 the availableHeight variable.
We should just use -1 like the code was doing before that patch.

BUG=648880
TEST=fast/table/quirks-mode-percent-height.html

Committed: https://crrev.com/5b0f27ec040f501eb7af22ea017db9f4f0c902dd
Cr-Commit-Position: refs/heads/master@{#421145}
==========

[commit-bot: I haz the power, 2016-09-27 08:10:01]

Patchset 1 (id:??) landed as
https://crrev.com/5b0f27ec040f501eb7af22ea017db9f4f0c902dd
Cr-Commit-Position: refs/heads/master@{#421145}