Patch for PluginLogic pre-initializing.

Patch for PluginLogic pre-initializing.

  * This patch perform PluginLogic initializing before webkit loader starts working.
    The initializing includes a loading plugin so file.
    This work helps that webapp is launched more fast.

  * This commit must be merged with below.
    - https://tizendev.org/gerrit/#/c/28449/

[Issue#] N/A
[Problem] N/A
[Cause] N/A
[Solution] Patch for PluginLogic pre-initializing.
[SCMRequest] must be imported with wrt-plugins-common

Change-Id: I7941332d313c8c1b6c058c98bbd0347e7df66cf9