Performance increase in thumbnail handling

Allow for 160*120 thumbnails which is what cameras commonly
generates. The constants for the micro thumbnail were set to other
values, resulting in recalculations of the thumbnais, which
takes time.

This change only affects the maximum size of the temporary image,
when choosing whether to use the EXIF thumbnail or decoding and
downsampling the full image. Without this change, it will choose
an x16 downsampling of the full image over an x2 downsampling of
the EXIF thumbnail, after the change it will prefer the EXIF
thumbnail.

Cf the DCF specifications at http://www.exif.org/dcf.PDF,
"3.3.6. DCF basic thumbnail data structure, (C) Pixel count"

Tested by running DDMS and measuring the time required to create
a thumbnail. This was 220-280 ms prior to change, < 20 ms after.

Change-Id: I59c753493f947e920bad3fde5eeed5d49d509863
FIX Null Pointer Exception on dialog cancel

Null Pointer Exception occurs because mWebViewCore instance
is made to null while calling destroyJava(). When
1.webview hosting activity goest to background, without calling webview onPause().
2. If app is launched again (having launchmode:singletask ) and another activity (not  webview hosting) comes on top top.
3. It destorys the previous activity holding webview which internally tries to cancel the dialog, but webviewcore instance is null.
Null pointer exception is raised.

Change-Id: Idbcd30d0b0d4a35819444bbaa5c73cced8bb35a3
Signed-off-by: Amit Kumar <amitkecian@gmail.com>
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>