Web Inspector: Fix how Popover animates

Web Inspector: Fix how Popover animates
https://bugs.webkit.org/show_bug.cgi?id=136353

Patch by Saam Barati <sbarati@apple.com> on 2014-08-29
Reviewed by Timothy Hatcher.

Popovers currently don't animate properly because they use
window.requestAnimationFrame which won't fire its callback
while the inspector is paused in the debugger. This patches
switches the callback mechanism to setTimeout and also changes
how a Popover's anchor animates to prevent visual glitches.

Popover also has a new function that allows a new target
frame and new content to be set simultaneously and to
animate to show the new content while changing the
location of the popover frame.

SourceCodeTextEditor uses Popover's new API for animating
between popovers when paused in the debugger. SourceCodeTextEditor
also now ensures proper balancing of popover tracking event
listeners.

* UserInterface/Views/Popover.js:
(WebInspector.Popover.prototype.present):
(WebInspector.Popover.prototype.presentNewContentWithFrame):
(WebInspector.Popover.prototype.dismiss):
(WebInspector.Popover.prototype._update):
(WebInspector.Popover.prototype.drawBackground):
(WebInspector.Popover.prototype._animateFrame):
(WebInspector.Popover.prototype._drawFrame):
(WebInspector.Popover.prototype._addListenersIfNeeded):
(WebInspector.Popover.prototype._animateFrame.drawBackground): Deleted.
* UserInterface/Views/SourceCodeTextEditor.js:
(WebInspector.SourceCodeTextEditor.prototype._showPopover):
(WebInspector.SourceCodeTextEditor.prototype._dismissPopover):
(WebInspector.SourceCodeTextEditor.prototype._trackPopoverEvents):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@173117 268f45cc-cd09-0410-ab3c-d52691b4dbfc