IDL compiler: [CheckSecurity=Frame] interfaces (initial)

This adds support for [CheckSecurity=Frame] interface,
but not for [CheckSecurity] + [DoNotCheckSecurity], as in:
[CheckSecurity=Frame] interface { [DoNotCheckSecurity] void foo(); };
(i.e., DomainSafeFunctionGetter/Setter).

BUG=239771

Review URL: https://codereview.chromium.org/61523003

git-svn-id: svn://svn.chromium.org/blink/trunk@162286 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Enable fastUseReject for tree boundary crossing rules.

Tree boundary crossing rules have one of ::content, ^, or ^^.
We can enable the filter for rules containing ^ or ^^,
but cannot enable the filter for rules containing ::content.

To disable the filter for ::content, just destroy hash table in collectIdentifierHashes
when finding ::content.

BUG=314300

Review URL: https://codereview.chromium.org/74783005

git-svn-id: svn://svn.chromium.org/blink/trunk@162288 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: remove [CPPPureInterface]

[CPPPureInterface] is legacy cruft, nop (no use in compiler),
one use in an IDL file; removing.

BUG=239771

Review URL: https://codereview.chromium.org/75463010

git-svn-id: svn://svn.chromium.org/blink/trunk@162289 bbb929c8-8fbe-4397-9dbb-9b2b20218538