Remove WeakNodeMap from oilpan bulids

- WeakNodeMap.{h,cpp} is only used by InspectorNodeIds.{h,cpp}.

- WeakNodeMap is not needed at all in oilpan bulids, because in oilpan we can just use on-heap hash maps of weak members.

- This CL removes WeakNodeMap from oilpan builds. As far as I can tell, the simplest way of doing that is just to comment out WeakNodeMap using #if !ENABLE(OILPAN) and add another implementation of InspectorNodeIds' methods for ENABLE(OILPAN).

BUG=340522

Review URL: https://codereview.chromium.org/387473002

git-svn-id: svn://svn.chromium.org/blink/trunk@177831 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [Sources] Show proper shortcut in the Pause/Resume button tooltip

The action's shortcut descriptors should be used to compute the textual
shortcut representation, rather than an empty array.

R=aandrey, vsevik
BUG=392431

Review URL: https://codereview.chromium.org/385563002

git-svn-id: svn://svn.chromium.org/blink/trunk@177832 bbb929c8-8fbe-4397-9dbb-9b2b20218538
WebGL: Refactor active context management.

This CL makes WebGL lost&retore code more succinct.

1. Deactive a context in loseContextImpl(), instead of dispatchContextLostEvent().
Because of
a) Prevent inconsistent state. Currently, activeContext() vector can store a lost
context due to this, so oldestContextIndex() needs to check if active context is
lost. Now we don't need redundant lostContext check. In addition, it does not
make sense that active context list can store a lost context.
b) In the same sense, only maybeRestoreContext() actives a context like loseContextImpl()
in this CL.

2. Don't call activeContexts().remove() adhoc.
Only deactiveContext() calls activeContexts().remove() like only activeContext()
calls activeContexts().append().

3. Change the logic of dispatchContextLostEvent().
Currently, when m_contextLostMode != RealLostContext, a context is added to
forcibly evicted list, in which the context will be restored when another
context is destructed. However, we start the restore-timer when
the context is lost due to AutoRecoverSyntheticLostContext also. It means
AutoRecoverSyntheticLostContext can restore twice. So this CL changes a context
to be added into forcibly evicted list only if SyntheticLostContext.

BUG=392274

Review URL: https://codereview.chromium.org/251373005

git-svn-id: svn://svn.chromium.org/blink/trunk@177833 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Popup open and hide using Alt+KeyDown

HTMLSelect to open popup when key combination alt+keydown. It does not select any element, just opens or hide popup.

Once popup is open, default handler of the popup handles key event. For that reason hide popup is handled in PopupListBox.

This behavior is compatible with firefox behavior.

R=tkent, keishi
BUG=383818
TEST=On Alt+keydown open popup and check if visible. On again press of Alt+keydown, close popup.

Review URL: https://codereview.chromium.org/368023003

git-svn-id: svn://svn.chromium.org/blink/trunk@177834 bbb929c8-8fbe-4397-9dbb-9b2b20218538