[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
The big in-browser tests classes clean-up

Removed lots of unneeded code and simplified some of the remaining.
[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.
[Tizen] Make the location provider implementation self-contained.

One of the problems with ld.bfd described in 7b83793 ("[Tizen] Start
using binutils-gold for linking Crosswalk again") was that when building
Crosswalk with -Dcomponent=shared_library ld.bfd would complain that
libcontent.so was missing symbol content::NewSystemLocationProvider().

Even though ld.gold links our binaries correctly, we are still having
problems _running_ them because the runtime linker cannot find an
implementation for that symbol (gyp causes lib/libcontent.so to be
passed after the .a archive containing the implementation in
content::NewSystemLocationProvider() from Crosswalk).

We can solve this the right way by making use of the infrastructure that
has been present in Chromium since at least M35 (!!): just override
ContentClientBrowser::OverrideSystemLocationProvider() and instantiate
Tizen's implementation there.
Merge pull request #2673 from rakuco/cleanup-aura-gyp-deps

gyp: Cleanup Aura-related files and dependencies.
Merge pull request #2671 from pozdnyakov/rename_RuntimeContext

Rename RuntimeContext to XWalkBrowserContext
Merge pull request #2674 from rakuco/tizen-implement-locationprovider-without-touching-content

[Tizen] Make the location provider implementation self-contained.
Roll DEPS.xwalk: chromium_crosswalk_rev (abbaeb8 -> ea46c0b)

ea46c0b Merge pull request #215 from pozdnyakov/XWALK_2789
17ac09e Fix GPU process crash
Bump version to 11.39.256.0
Merge branch 'master' of github.com-crosswalk:crosswalk-project/crosswalk