[Android] Implement the http authentication in xwalk default client.

  The implementation is to provide the http anthentication
funtions to support the authentication requirement of some
web site related to username and password, covering the
following:
1 Import and implement a general class of HttpAuthDatabase
  to support common http authentication database interfaces.
  This class imports the android sqlite database to handle
  the username and password data on demand.
2 In default xwalk client, implement the method of
  setHttpAuthUsernamePassword() by calling the related method
  of HttpAuthenDatabase instance to set the username and password.
3 In default xwalk client, implement the method of
  getHttpAuthUsernamePassword() by calling the related method
  of HttpAuthenDatabase instance to query the username and password.

BUG=#784, #787
Add application extension and getManifest(), getMainDocument() API support

The application extension is an internal extension to handle application level
APIs(e.g., runtime events, manifest, package management, etc.).

In this commit two APIs is added, one is xwalk.application.getManifest(see
http://developer.chrome.com/apps/runtime.html#method-getManifest), the other is
xwalk.application.getMainDocument(see
http://developer.chrome.com/apps/runtime.html#method-getBackgroundPage).

We use asynchronous calls for both of these two APIs. getManifest() will
retrieve current running application's manifest dictionary value and post the
value to renderer. getMainDocument() utilizes ApplicationNativeModule to get
RenderView from the main document's routing ID, then return its main frame
global JS object.
[Tizen] add the 'gst-plugins-atomisp-devel' buildrequires to spec.

chromium needs the header and lib files exported from this package to drive the
camera device on Tizen 2.1 hardware platforms.

BUG=#864
Add application browser test base class and application API browser test

ApplicationBrowserTest is a base class for application browser test. Currently
it only provides Runtime status check. It will support other application test
utilities after shared browser process model is supported.

In this commit getManifest() and getMainDocument() API tests are added.
Merge pull request #923 from wang16/roll_deps

Bump chromium-crosswalk in DEPS.xwalk.
[Android] Refine the xwalk_core_test_apk target

This fix is to refine the test target to make it more cleaner to add
HTML testing file as apk asset file. Right now, when adding a new HTML
file for testing, you just need to update the 'sources' list without
adding a new entry item in 'copies' list.
Merge pull request #612 from seanlong/xiang_api

[Runtime] Add application extension skeleton and getManifest, getMainDocument API support
[Extensions] Refactoring XWalkExtensionService::RegisterExtension

Nowadays our XWalkExtensionService is only capable of handling
one RenderProcess. Thus, it only has one in_process XWalkExtensionServer
for handling internal extensions. Soon enough this will considerably
change and we will have to be capable of handling one in_process
XWalkExtensionServer per RenderProcess.

This patch is the first step towards this: internal extensions
will be created directly by the XWalkExtensionService::Delegate
"on-demand" every time a new in_process XWalkExtensionServer
is created for a new RenderProcess and it is time to register
the internal extensions on it.

The entity implementing XWalkExtensionService::Delegate is
XWalkBrowserMainParts. This way we keep the old behavior and design
not polluting XWalkExtensionService.

Necessary adjustments were made to RegisterExtensionsCallback and
browser_tests for the same reason.
Enable multithreaded GPU compositing of web content by default.

Enable multithreaded GPU compositing of web content by default, this also enables pinch gesture support on Tizen.
Merge pull request #933 from pozdnyakov/EnableThreadedCompositing

Enable multithreaded GPU compositing of web content by default.
[Extensions] Remove unused function
[Tizen] Fix Glib assertion due to appcore_context.

This patch get rid of following log:
[ERROR:browser_main_loop.cc(228)] GLib: g_source_destroy: assertion `source != NULL' failed

AppcoreContext::Initialize() fails when we launch xwalk in the shell. e.g. > xwalk
It is because appcore_init() can success only if registered application (e.g.
web applications) is launched.

This patch handles the exception that AppcoreContext::Initialize() fails.
[Extensions][Android] Make CreateExtension call XWalkExtensionService directly

XWalkBrowserMainParts is now a XWalkExtensionService::Delegate, meaning that
XWalkExtensionService will call RegisterInternalExtensionsInServer everytime
a new in_process XWalkExtensionServer is created (for a new RenderProcess).

Therefore, XWalkExtensionService::RegisterExtension() has been removed
and XWalkExtensionAndroid will now need to register its extensions on
XWalkBrowserMainParts so them can get correctly registered on-demand
by XWalkExtensionService.
Merge pull request #934 from cmarcelo/remove-dead-code

[Extensions] Remove unused function
[Extensions] Use a vector instead of a map for extension modules

In XWalkModuleSystem, use a vector instead of a map for extension
modules. The number of modules is small and we'll benefit from being
able to easily get sorted iteration later to identify the extension
modules that can be loaded on demand.
Fix build for Windows.

Windows switched to Aura therefore we need to remove the old code
path and use the generic method to access the title. The compilation
failure was due to the fact that NativeWindow type is not anymore
a HWND.

BUG=936
Merge pull request #910 from jeez/refactor-register-extension

[Extensions] Refactoring XWalkExtensionService::RegisterExtension
Merge pull request #937 from cmarcelo/extension-modules-vector

[Extensions] Use a vector instead of a map for extension modules
Bump version to 2.31.21.0
Merge pull request #931 from hmin/refine-test-target

[Android] Refine the xwalk_core_test_apk target