Improve manifest handlers unit test utilities

This patch introduces functions creating default configuration
data for both manifest types (TYPE_MANIFEST and TYPE_WIDGET).
runtime: Add aura-only native support

This CL brings aura-only native support for the browser runtime, where views
toolkit dependency is opt out. This is particularly useful for embedded and
limited systems, where the runtime is used always as a fullscreen application
to the host window system. This is aimed to work with Ozone DRI or GBM
implementations.

Testing was performed on Ubuntu Linux 14.04 platform.

TEST= $ python xwalk/gyp_xwalk -Dchromeos=0 -Duse_ozone=1 -Dembedded=1 -Duse_udev=1 -Dozone_platform_gbm=1 -Dozone_platform_wayland=0 -Ddisable_nacl=1
      $ ninja -j16 -C out/Release xwalk
      $ ./out/Release/xwalk --ozone-platform=gbm http://hexgl.bkcore.com/play/
runtime: Add cmd line option for changing native host window bounds

Ideally we would like to use ui::DisplayConfigurator for hotplug the monitors
and set the host window bounds automatically based on their mode sizes. That's
not possible though cause Crosswalk embedded solution doesn't fetch ChromeOS
dependencies, which is where ui::DisplayConfigurator situates.

Our solution here therefore is to pass through command-line options the native
bounds, using --xwalk-host-window-bounds=800,600 (or whatever is the
appropriated monitor resolution). One would also just link this newly option
with sysfs output like --xwalk-host-window-bounds=`cat /sys/class/graphics/fb0/virtual_size`
[Tizen] Fix widget namespace value validation.

According to widget W3C spec (http://www.w3.org/TR/widgets/#namespace), the namespace cannot be absent or invalid.
If namespace is absent or wrong, the widget should be treated as invalid package and installation should be failed.

BUG=XWALK-2978
xwalk-launcher: Simplify dependency on 'gio' gyp target.

Both Linux and Tizen depend on system.gyp:gio, so we can depend on it
unconditionally and simplify the gyp code.
Merge pull request #2665 from rakuco/simplify-gio-unix-gyp-dependency

xwalk-launcher: Simplify dependency on 'gio' gyp target.
Merge pull request #2637 from tiagovignatti/embedded

Crosswalk embedded support
The big in-browser tests classes clean-up

Removed lots of unneeded code and simplified some of the remaining.
Merge pull request #2659 from tweglarski/UnitTestUtilImprovements

Improve manifest handlers unit test utilities
[Tizen] xwalk.gyp: Do not special-case virtual_root_provider_tizen.cc.

There is no need to put that file inside a "tizen==1" condition, files
terminating in _tizen.cc are automatically excluded from the build on
other platforms.
[Tizen] gyp: Centralize the dependency on libtzplatform-config.

pkg-config was being used to get libtzplatform-config's flags in both
build/system.gyp and xwalk.gyp. Do that in a single place,
build/system.gyp, instead, to reduce this needless duplication.

Since libtzplatform-config was part of the catch-all "tizen" target in
system.gyp, it has been split into its own separate target so that code
that only needs libtzplatform-config does not end up depending on
several other Tizen libraries as well.
Merge pull request #2667 from pozdnyakov/tests_cleanup

The big in-browser tests classes clean-up
Merge pull request #2668 from rakuco/tizen-move-file-to-generic-list

[Tizen] xwalk.gyp: Do not special-case virtual_root_provider_tizen.cc.
Bump version to 11.39.255.0
Merge branch 'master' of github.com-crosswalk:crosswalk-project/crosswalk
Merge pull request #2669 from rakuco/tizen-centralize-tzplatformconfig-gyp-dep

[Tizen] gyp: Centralize the dependency on libtzplatform-config.
Merge pull request #2655 from yejingfu/fix-widget

[Tizen] Fix widget namespace value validation.
Rename RuntimeContext to XWalkBrowserContext

Since it's a browser context actually.
gyp: Cleanup Aura-related files and dependencies.

* Stop manually excluding _aura.cc files from the build, this is done
  automatically by Chromium's filename_rules.gypi. Ditto for files
  ending in _views.cc.

* Remove the dependency on the "aura_test_support" and "wm" targets. Not
  only does depending on a test target even when no tests are being
  bring a ton of additional dependencies, but neither targets seem to be
  needed at all, and were probably only needed in an earlier version of
  commit 336c03a ("runtime: Add aura-only native support").
DEPS.xwalk: Roll chromium-crosswalk (35b73bc -> abbaeb8).

abbaeb8 Merge pull request #214 from rakuco/revert-tizen-geolocation-changes
2d50c47 Revert Tizen changes to support changing the system location provider.

A proper implementation using those changes comes in the next commit.