[Runtime] WARP security mode should be enabled by default.

According to the W3C widget spec, http://www.w3.org/TR/widgets-access/,
it said: In the default policy, a user agent must deny access to network
resources external to the widget by default, whether this access is
requested through APIs (e.g. XMLHttpRequest) or through
markup (e.g. iframe, script, img). Means if there's no access tag in
config.xml, all external requests should be blocked.

BUG=XWALK-1772
[Android] Expand the path of app_root in LaunchScreen

If the provided path of manifest.json is not absolute, the launch screen image can not be found
and will cause build fail.
Change to use ManifestParser.input_path.

BUG=XWALK-1795
[Android] Launch Screen test

The patch of Launch Screen auto test is missing.
Re submit the patch.

BUG=XWALK-1805
[Android] Fix null callback issue in XWalkView.evaluateJavaScript.

In case that the callback is a `null` value, XWalkView should behave normally and
same as Android WebView.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1815
[Android] Pre-initialize the CPU information for ARM platform

On ARM platform, the cpu information is fetched from /proc/cpuinfo
which requires the right to allow accessing IO. Howerver, in Crosswalk,
the IO/IPC thread is not allowed to IO access unless
ThreadRestriction::SetIOAllowed(true) is called explicitly.

This fix is to pre-initialize the CPU info in advance to avoid thread
restrictions on reading /proc/cpuinfo.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1836
[Android][Script] Fixes in XWalk debugging script

The env variable CHROME_SRC is not exposed, use ENVSETUP_GYP_CHROME_SRC
instead
Native File System API

Completed features list:

Create file
Read file
Write file
Remove file
Create Directory
List Directory Entries
Remove Directory

BUG=https://crosswalk-project.org/jira/browse/XWALK-672

Support for Android is coming soon.
Merge pull request #1889 from shawngao5/native_file_system

Native File System API
[Tizen][Runtime] Fix lose symbolic link after update.

Before PR https://github.com/crosswalk-project/crosswalk/pull/1933
we update an application by uninstall and install.

And after this PR update have independent logic, so we will lose
symbolic link when update an application.
Merge pull request #2016 from kurli/launch-screen-test-case

[Android] Launch Screen test
Merge pull request #2029 from sqliu/fix-evaluate-js

[Android] Fix null callback issue in XWalkView.evaluateJavaScript.
[Tools] Fixed xwalk_android_gyp issue

according to the chromium upstream patch d9584323 and 50f36a01,
the community decided to stop exporting CHROME_SRC and
ENVSETUP_GYP_CHROME_SRC out of build/android/envsetup.sh, which
will break xwalk_android_gyp.
So we need to get rid of the dependency on those exported variables
in our own script.
Merge pull request #2028 from hmin/script

[Android][Script] Fixes in XWalk debugging script
Merge pull request #2032 from CooderIan/fix_symbolic_link

[Tizen][Runtime] Fix lose symbolic link after update.
DEPS.xwalk: Roll v8-crosswalk (262b54e -> c4640c3).

c4640c3 Merge pull request #32 from dp7/master
9f30235 Merge pull request #34 from fenghaitao/setTruncatingFlag
69be78f Set kTruncatingToInt32 flag if one of the SIMD operand requires Integer32
773c161 Merge pull request #33 from fenghaitao/master
ca3023f Fixed a typo: psrlq -> psrldq.
2a06d56 V8 profiling patch rebased on Chromium v36
6756718 Merge pull request #31 from huningxin/fix_int32x4_select
c537192 Merge pull request #30 from huningxin/fix_ia32_debug
2daf654 Fix SIMD.int32x4.select to return and accept input type as float32x4
03a03f2 Fix ia32 debug build issue.
a0f0edc Merge pull request #22 from rakuco/backport-urlretrieve-fix
c2d1700 Backport r21402 from the bleeding_edge branch.
Merge pull request #2033 from jondong/envsetup

[Tools] Fixed xwalk_android_gyp issue
Merge pull request #1994 from takethathe/warp

[Runtime] WARP security mode should be enabled by default.
Merge pull request #2035 from rakuco/v8-xwalk-roll

DEPS.xwalk: Roll v8-crosswalk (262b54e -> c4640c3).
Bump version to 7.36.150.0
Merge pull request #2027 from hmin/cpu

[Android] Pre-initialize the CPU information for ARM platform