[AduioPlayer] Ignore current time update from the audio element in smarter way

Previously, it was detected by the differential of new value and old value, but it causes the disconnection when high load (Problem #3 in crbug/346314). Instead, we use the cached value of the last update from the audio element. This should solve the issue.

BUG=346314
TEST=manually testted

Review URL: https://codereview.chromium.org/177073017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254072 0039d316-1c4b-4281-b951-d872f2087c98
Convert the SelectPopupDialog to be non-static.

BUG=344740

Review URL: https://codereview.chromium.org/180423002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254073 0039d316-1c4b-4281-b951-d872f2087c98
Remove RenderFrameObserver from WebMediaPlayerImpl and simplify destruction path.

The history of this goes back quite a ways to a much simpler time and place.

r9069 added the original instance of MessageLoopDestructionObserver to prevent media code from using a stale MessageLoop pointer. MessageLoopProxy would have been handy here, but it was only invented years later in r45907. Now, it might have been possible to remove MessageLoopDestructionObserver then but media code was plagued with hacky shutdown code. There were even changes such as r117742 that added methods like VideoDecoder::PrepareForShutdownHack() to formalize the hacky shutdown code.

Eventually, sleeves were rolled up and the shutdown code was redone and VideoDecoder::PrepareForShutdownHack() was removed in r156525. At this point in time media code was still using MessageLoop instead of MessageLoopProxy. It wasn't until r185400 that media code finally switched over to MessageLoopProxy.

Unfortunately MessageLoopDestructionObserver stuck around, likely because no one remembered if it was still needed. Eventually it was replaced with RenderViewObserver in r240125 and then finally RenderFrameObserver in r248321.

Well it turns out we haven't had to worry about this particular shutdown path for a while. Let it rest in peace.

BUG=341186

Review URL: https://codereview.chromium.org/181063005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254074 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 254074