[SMACK] Label xwalk binaries with User domain

*In order to make all xwalk binaries running with same User domain
 label, we enforce "exec_label" property for them.
[Runtime] Add i18n support for widget info

After locale was changed, we need to update widget info.
So that application widget api will get a localiation value.
[Tizen][Runtime] Update application information in DBus service when
updating.

When updating application, the information cached in DBus service should
be synced as well.

BUG=XWALK-1231
Stop checking for `tizen_mobile' in gyp wherever possible.

tizen_mobile has not been defined ever since we dropped support for
Tizen 2.x in 58841e7393074ea40e9a86bb55e8025256cf5af5, so the check has
been dead for a while.

Helps fix XWALK-1625.
Remove content_resource.pak from pak list.

The content_resources.pak only contains html/js/css files for chrome webui.
As the webui is not needed for xwalk, so just ignore it.
This can reduce size of xwalk.pak for about 150k

BUG=
Revert "[Android] Implement mixed resources to fix resource not found"

This reverts commit fbe4a5796cfa27a214a2ef2dc3e7cde3719d9c43.
[Android] Use XWalkBaseActivity for each demo in Crosswalk Sample

1. XWalkBaseActivity will control the XWalkView lifecycle, such as onHide, onShow and onDestroy.
   All other demos need to override from this base activity.
2. Add CrosswalkSample to xwalk_builder. (it's not the final solution, will track it with XWALK-1593)

TODO: Removed alert in manifest demo, it will cause crash when onDestroy() is called.
      XWALK-1639

BUG=XWALK-1631
[Android] Fix resource loading issue of shared mode

Previously, xwalk_runtime_client_shell incorrectly packages
all xwalk resources within it, which hide the resource
loading issue of shared mode.

In commit fbe4a5796, attempting to fix this by creating
MixedResources and override "getResources()" of Context.
But in chromium, there exist bunch of code that get resources
from application context.

In this fix, xwalk will provide an overridden Application
which return XWalkMixedResources for getResources().

In such case, all resource loading within XWalkRuntimeLib will
try first loading from library's Context and then from app's
if not found.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1609
Fix Mac build.

-Turn off NaCl support for now.
-Fix compile issues in plugin code.
-Fix various code issues reported by clang.
[Android] Fix the timer resuming issue

Removing the flag indicating if the timer is paused since the renderer
resources are not destroyed when the activity is destroyed, it is
somewhat by design, and the java side flag will cause inconsistent
state with native side renderer side.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1653
Merge pull request #1902 from kurli/sample-base-activity

[Android] Use XWalkBaseActivity for each demo in Crosswalk Sample
[Android] Add test cases for load().

This patch is to add test cases for load().
It conatins several URL schemes like 'http:', 'https:', 'file:'
and others.
[Android] Add the sample code for demonstrating Embedding API

Add the sample code for demonstrate the usage of some Crosswalk Embedding API, covering ones:
1. XWalkView.getAPIVersion()
2. XWalkView.getXWalkVersion()
3. XWaklNavigationItem.getUrl()
4. XWaklNavigationItem.getOriginalUrl()
5. XWaklNavigationItem.getTitle()

BUG=XWALK-1617
Merge pull request #1920 from wuhengzhi/load_test

[Android] Add test cases for load().
Merge pull request #1907 from wang16/fix_share_file_input

[Android] Fix resource loading issue of shared mode
[Android] Disable the test cases for remote url.

Since the device issue, it can not access the network, so disable
the two test cases for load(). It will be enabled later.
[Android] Correct the usage of all_dependent_settings for core library

Previously, the all_dependent_settings is incorrectly used
in xwalk_core_library.gypi.
It's not used to include all the settings for some target's
dependencies. It's actually do settings for all the targets
depends on the one declares all_dependent_settings.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1575
[Android] Close presentation content already opened when destroying

* Destroy the presentation content to clean up the resources occupied by
  XWalkView to avoid resource leaking
* Refactor some code

BUG=https://crosswalk-project.org/jira/browse/XWALK-1633
Merge pull request #1908 from takethathe/allow-navigation

[Tizen][Runtime] Add a new allow-navigation policy type.
[Android] The app UI is locked if users cancel the JS alert dialog.

This is because the onClickListener of the cancel button is not handled.
As a result, the UI is blocked. Besides, onCancelListener can handle
back key so we don't have to override it.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1627