Audio continue to played even if paused manually

Currently, audio will resume playing after a phone call
or notification even if the user had manually paused playback.

This patch addresses that by introducing a new player state
to distinguish the user pausing playback and the browser
losing audio focus for some other reason. Audio will only
 resume if the browser temporarily lost audio focus and
not when the user has manually paused playback.

Change-Id: I9e8beaedb0fcc5afe920068297ed9c387eab2ac8
Signed-off-by: Roger Chen <cxr514033970@gmail.com>
Fix NPE when pasting non-text from Clipboard

When copying a link from a bookmark and then pasting it into
a textfield a NullPointerException will occur.
A ClipData.Item is not guaranteed to always contain a text string
and therefore getText() can be set to null.

Using method coerceToText() instead of getText() makes sure that
a text string is always returned.

Change-Id: I81343c0371835a3a7a52045dcd1760e69e59a967
Can not mark the same content of browser page after copy

Marking a text on the web page and then press copy works,
but trying to mark the same text again does not work.
The reason for this is that the selection never gets
cleared in webkit.
The fix, calling cleaSelection in the onDestroyActionMode.
Also added clearSelection when getting an
onConfigurationChange.

Change-Id: I59b384cb5441b6a3a05007ea7e77f9699889a87c