Fix the problem that the favicons on the history page are shown ramdomly when the page is scrolled.

Steps to reproduce:
1. Visit some URLs to fill the history page.
2. Go to the history page.
3. Scroll up and down repeatedly.

What happened:
The favicons on the left side of the history page are shown ramdomly.

Change-Id: I243ec67899b13c5482e1503f7eab23dd9a5aa1f5
Signed-off-by: Sungmann Cho <sungmann.cho@navercorp.com>
Handle DownloadManager expceptions

Handles illegal state exceptions thrown by DownloadManager
on two ocassions:
* the directory sdcard/Downloads is an ordinary file
* could not create dirctory sdcard/Downloads

Change will log an error, additionally toast with information
will pop up.

Change-Id: If853d3218a188bc77c187362a70697126b90989d
Browser: Fix browser force close

Issue: Cursor was accessed by handler thread
       when it was closed. During Orientation change,
       BrowserBookmarksPage#onDestroyView is called
       which clears all the loaders [and cursors].
       Simultaneously ThreadedCursorAdapter#loadRowObject
       is getting called which then calls
       BrowserBookmarksAdapter#getRowObject
       where closed cursor is accessed and force close happens.

Fix: Synchronized cursors wrt main thread and handler thread.
     Checked mCursorAdapter for invalid conditions

CRs-Fixed: 576176
Change-Id: I9f16c2f1a55f35e8256bbf56afce3538850f9d42
fix browser blue textfield

Change-Id: I6f7fb8b0ff61d4d9d78a8580450f7d299c41d449