[EFL] Add ewk_view_device_pixel_ratio_set
https://bugs.webkit.org/show_bug.cgi?id=118521

Reviewed by Gyuyoung Kim.

Source/WebCore:

No new tests, covered by existing tests.

* dom/ViewportArguments.cpp: Remove PLATFORM(EFL) not to use deprecatedTargetDPI
* dom/ViewportArguments.h: Ditto.
* platform/efl/EflScreenUtilities.cpp: Removed getDPI() which is not used anymore.
* platform/efl/EflScreenUtilities.h: Ditto.

Source/WebKit/efl:

ewebkit and ewebkit2 have different approach about getting device pixel ratio.
ewebkit depends on deprecatedTargetDPI and ecore_x_dpi_get,
but ewebkit2 use Page::deviceScaleFactor.

This patch will add ewk_view_device_pixel_ratio_set and use Page::deviceScaleFactor()
instead of ViewportArguments::deprecatedTargetDPI like ewebkit2.

* ewk/ewk_view.cpp:
(_ewk_view_priv_new):
(_ewk_view_viewport_attributes_compute): Use Page::deviceScaleFactor().
(ewk_view_viewport_attributes_get): Ditto.
(ewk_view_device_pixel_ratio_set): Added.
(ewk_view_device_pixel_ratio_get):
* ewk/ewk_view.h:
Update document of ewk_view_device_pixel_ratio_get (from ewebkit2) and
added ewk_view_device_pixel_ratio_set.

Tools:

* EWebLauncher/main.c: Added new option(-r) to test device pixel ratio.
(windowCreate):
(parseUserArguments):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@152523 268f45cc-cd09-0410-ab3c-d52691b4dbfc