[SysApps][Android] Refine display attributes based on latest spec

SPEC=http://www.w3.org/2012/sysapps/device-capabilities/
BUG=XWALK-1309
[Extensions] Add command line switch xwalk-extension-cmd-prefix

This will prepend the contents of this flag to the command line
when starting extension process, it works as same as the switch
"--renderer-cmd-prefix", could be useful if we need to debug
the extension process at its very beginning.
Useful values might be "valgrind" or "xterm -e gdb --args".

Also modified the child path flag which is used to retrieve the
child process' execution file according to the extension command
line prefix on linux. In most cases we need to use CHILD_ALLOW_SELF
to exec child process from /proc/self/exe to prevent chromium's
autoupdate feature to change the file out from underneath; For the
case of xwalk-extension-cmd-prefix, as we suppose to override the
command line to load the app directly, we need to use CHILD_NORMAL
to exec child process from its real app path.
gyp_xwalk: Stop running GN.

GN is not a hard dependency for generating the build files in M34, and add
unnecessary checking for dependencies in the host system when we're building
for Android and Tizen.

In addition, the hack in place there to avoid running it with the make
generator will be rendered useless once we start using Ninja on Tizen.
[Tizen] Start using Ninja to build Crosswalk on Tizen.

All Tizen profiles finally have Ninja as a package, and commits 096e68d and
9c9419b did all the required heavy-lifting to allow us to use the ninja gyp
generator instead of the make one to build the Crosswalk RPM.

Incremental builds should still be supported just fine, but the first build
with ninja will start from scratch due to the move to a different build
system.

One meaningful change is that we do not pass -Duse_system_icu=1 anymore and
instead use Chromium's copy. While that is not perfect from a packaging
perspective, it is currently necessary due to problems with the code (see
crrev.com/104793004 and crrev.com/124003004).

Moving to Ninja is a required step for us to move to Chromium 35, since the
make gyp generator is unsupported from this version on.

BUG=XWALK-1025
Merge pull request #1786 from rakuco/ninja-on-tizen

At long last, start using ninja to build Crosswalk on Tizen.
Bump version to 6.34.114.0
xwalk.gyp: Fix building for Android without webkit debug symbols

Fix missing symbols at linker stage when building with option
'remove_webcore_debug_symbols' by adding the required dependencies
to the 'xwalk_runtime' target.
dbus_manager_tizen: Remove useless glib include
xwalk.gyp: Explicitly add jsoncpp dependency

The lack of this dependency was generating error, required by
ScreenOrientationExtension.
runtime/browser: Fix header file changes

Offending CL:
https://codereview.chromium.org/174803002
Merge pull request #1793 from r0b5t4/foo

xwalk.gyp: Fix building for Android without webkit debug symbols
Merge pull request #1794 from tiagovignatti/for-upstream

For upstream
Bump version to 6.34.115.0
[Tizen] packaging: explicitly disable GNOME Keyring support.

gnome-keyring isn't packaged for Tizen, and we are not interested in using
it at the moment anyway.

While support for it is disabled by default when Aura is used in M34, this
is not the case anymore since Chromium r251992 (part of M35). Prepare for it
by explicitly disabling the support in master so that the actual commit that
moves to M35 in crosswalk is smaller.
Merge pull request #1795 from rakuco/tizen-no-gnome-keyring

[Tizen] packaging: explicitly disable GNOME Keyring support.
Bump version to 6.34.116.0
Merge pull request #1780 from jondong/master

[Extensions] Add command line switch xwalk-extension-cmd-prefix
Merge pull request #1773 from halton/display_refine

[SysApps][Android] Refine display attributes based on latest spec
[Android] Support xwalk_host member for manifest.json

The xwalk_host member allow application developer to add URL
match patterns as white list for allow Cross-Origin access.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1353
[Android] Add tests for Cross-Origin XHR.

For embedded client test:
1. install XWalkRuntimeClientEmbeddedShell.apk
2. python build/android/test_runner.py instrumentation \
--test-apk=XWalkRuntimeClientEmbeddedTest -v -f \
testCrossOriginXhr

For shared client test:
1. install XWalkRuntimeLib.apk
2. install XWalkRuntimeClientShell.apk
3. python build/android/test_runner.py instrumentation \
--test-apk=XWalkRuntimeClientTest -v -f testCrossOriginXhr