Add use counters for the hspace/vspace attributes on <table>

There's also a Gecko bug and a spec bug on this:
https://bugzilla.mozilla.org/show_bug.cgi?id=725646
https://www.w3.org/Bugs/Public/show_bug.cgi?id=23039

BUG=277080

Review URL: https://codereview.chromium.org/260713002

git-svn-id: svn://svn.chromium.org/blink/trunk@173041 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[FastTextAutosizing] Remove FastTextAutosizer::enabled

FastTextAutosizer::enabled() is hot on profiles as it's called multiple
times per block. The places where the text autosizing setting can
change are well defined and all go through updatePageInfo() so this
patch removes enabled() entirely, replacing it with a check of
m_pageInfo.m_settingEnabled which is updated in updatePageInfo().

This patch is a followup to
https://src.chromium.org/viewvc/blink?view=rev&revision=173020

No new tests as this is just a refactoring.

BUG=367864

Review URL: https://codereview.chromium.org/265713002

git-svn-id: svn://svn.chromium.org/blink/trunk@173042 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Descend into inner tables for has-enough-text check.

BUG=366136,359788

Review URL: https://codereview.chromium.org/257273002

git-svn-id: svn://svn.chromium.org/blink/trunk@173043 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Do not initialize |v8::Context| on |ScriptController::updateDocument|.

Initializing |v8::Context| is a heavy operation, and should be avoided if necessary. This is meant to be delayed until first time |toV8Context| is called, but |ScriptController::updateDocument| was forcing creation.

This patch fixes the if branch so that it would not create a |v8::Context| if it does not exist.

BUG=368548, 368555

Review URL: https://codereview.chromium.org/263583002

git-svn-id: svn://svn.chromium.org/blink/trunk@173044 bbb929c8-8fbe-4397-9dbb-9b2b20218538