Oilpan: Refactor the IDL compiler in preparation for supporting a [GarbageCollected] IDL attribute

- In preparation for supporting a [GarbageCollected] IDL attribute, this CL changes IdlType.is_will_be_garbage_collected to IdlType.garbage_collected_type. IdlType.garbage_collected_type will return either of "GarbageCollectedObject", "WillBeGarbageCollectedObject" and "RefCountedObject". ("GarbageCollectedObject" will be implemented in the next CL.)

- This CL adds v8_types.cpp_ptr_type(), which returns a type of proper oilpan pointers.

- This CL changes toMemberNativeArray() to toRefPtrWillBeMemberNativeArray(). This was a bug of the current IDL compiler. Except for this, there is no change in generated code.

BUG=340522

Review URL: https://codereview.chromium.org/224713019

git-svn-id: svn://svn.chromium.org/blink/trunk@171065 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[SVG] Prevent setting *_UNKNOWN enum values.

After http://codereview.chromium.org/165893003, empty strings are
parsed as valid *_UNKNOWN enum values. They should be treated as invalid
values instead.

The CL removes *_UNKNOWN enum values from their respective
SVGEnumerationStringEntries to prevent successful parsing (and trigger
the invalid value fallback).

BUG=360430
R=schenney@chromium.org,kouhei@chromium.org

Review URL: https://codereview.chromium.org/227603009

git-svn-id: svn://svn.chromium.org/blink/trunk@171066 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: On-hover legend in FlameChart is not shown

BUG=360001

Review URL: https://codereview.chromium.org/228513004

git-svn-id: svn://svn.chromium.org/blink/trunk@171067 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Disable the support for pseudo-classes in matching criteria of content insertion points in author shadow trees.

This makes the implementation match the current spec. To support
<details>/<summary> elements, pseudo-classes are still supported in
UA shadow trees.

BUG=343332

Review URL: https://codereview.chromium.org/215103005

git-svn-id: svn://svn.chromium.org/blink/trunk@171068 bbb929c8-8fbe-4397-9dbb-9b2b20218538