Browser: fix cannot search music with yahoo/bing engine

When choose google search engine, this issue does not exist.
But when choose yahoo/bing/baidu search engine and search music
in Music Application, will not show normally but back to Music
App automatically for the same BrowserActivity instance is
destroyed after onNewIntent.

For this situation, will not finish this activity, just keep it.

CRs-Fixed: 494962

Change-Id: Ic53fa5814ab5596bd0bc630d6f3c8771931a8d80
Browser:Progress bar stopped in 5% when failed to load page

When browser opens a page with all data connections disabled,
it fails because of no connection, then it loads a local
error page. In this case the browser actually trys to load two
pages,the original web page and the local error page.
This makes special status transitions.
The common status transitions are
onPageStarted -> onPageFinished -> onProgressChanged(100)
In this case the special status transitions are onPageStarted
->onProgressChanged(100)->onPageStarted->onPageFinished.

Change-Id: Ibdb4605171f18ecfed289a4aa271b21b752d78d1
CRs-Fixed: 387629
Add setting to allow video playback without user gesture

Many web sites, such as those using HTML5 canvas to render video, use
javascript to initiate video playback.  Often, the video element is not
rendered, or if they are the media controls are not shown, thus
preventing the page from running properly.  Adding this option allows
those pages to work at the expense of increased bandwidth consumption.

Note that the default behaviour is changed to allow video to playback
without requiring user gesture.  If the user is concerned about
bandwidth, the behaviour can be reverted at any time by changing this
browser setting.

Change-Id: I13d7cd38069e0d54c6381517d1120965d71c92b4
CRs-Fixed: 426323

Conflicts:
	src/com/android/browser/BrowserSettings.java