Fix an issue that download entries in SharedPreferences is not removed when exiting app

Fix an issue that download entries in SharedPreferences is not removed when exiting app

SharedPreference.edit() creates a new editor.
So calling this method twice creates 2 different editors.
And the apply() call from the 2nd editor has no effect on the first editor.

BUG=459403
Committed: https://crrev.com/8afaa388f8005d441f7bbf0292ba7112124a6877
Cr-Commit-Position: refs/heads/master@{#316956}

[qinmin, 2015-02-17 23:55:25]

qinmin@chromium.org changed reviewers:
+ dtrainor@chromium.org

[qinmin, 2015-02-17 23:55:25]

PTAL

[David Trainor- moved to gerrit, 2015-02-19 00:54:28]

lgtm with suggestion

https://chromiumcodereview.appspot.com/930303003/diff/1/chrome/android/java/s...
File
chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
(right):

https://chromiumcodereview.appspot.com/930303003/diff/1/chrome/android/java/s...
chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java:203:
SharedPreferences.Editor editor = mSharedPrefs.edit();
Couldn't this be the following?  I'm fine either way though.

mSharedPrefs.edit().remove(DOWNLOAD_NOTIFICATION_IDS).apply();

[qinmin, 2015-02-19 01:05:56]

https://codereview.chromium.org/930303003/diff/1/chrome/android/java/src/org/...
File
chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
(right):

https://codereview.chromium.org/930303003/diff/1/chrome/android/java/src/org/...
chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java:203:
SharedPreferences.Editor editor = mSharedPrefs.edit();
On 2015/02/19 00:54:28, David Trainor wrote:
> Couldn't this be the following?  I'm fine either way though.
> 
> mSharedPrefs.edit().remove(DOWNLOAD_NOTIFICATION_IDS).apply();

Done.

[qinmin, 2015-02-19 01:06:13]

New patchsets have been uploaded after l-g-t-m from dtrainor@chromium.org

[qinmin, 2015-02-19 01:06:36]

The CQ bit was checked by qinmin@chromium.org

[commit-bot: I haz the power, 2015-02-19 01:07:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/930303003/20001

[commit-bot: I haz the power, 2015-02-19 01:28:44]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-19 01:29:34]

Patchset 2 (id:??) landed as
https://crrev.com/8afaa388f8005d441f7bbf0292ba7112124a6877
Cr-Commit-Position: refs/heads/master@{#316956}