[Qt] [WK2] Fix build after r141619
https://bugs.webkit.org/show_bug.cgi?id=108680

Reviewed by Benjamin Poulain.

Take a reference instead of a pointer for decoding functions.

* Platform/unix/SharedMemoryUnix.cpp:
(WebKit::SharedMemory::Handle::decode):
* Shared/CoordinatedGraphics/CoordinatedGraphicsArgumentCoders.cpp:
(CoreIPC::::decode):
(CoreIPC::decodeTimingFunction):
* Shared/CoordinatedGraphics/CoordinatedGraphicsArgumentCoders.h:
* Shared/CoordinatedGraphics/WebCoordinatedSurface.cpp:
(WebKit::WebCoordinatedSurface::Handle::decode):
* Shared/CoordinatedGraphics/WebCoordinatedSurface.h:
(Handle):
* Shared/qt/ArgumentCodersQt.cpp:
(CoreIPC::::decode):
* Shared/qt/ArgumentCodersQt.h:
(CoreIPC):
* Shared/qt/LayerTreeContextQt.cpp:
(WebKit::LayerTreeContext::decode):
* Shared/qt/PlatformCertificateInfo.h:
(WebKit::PlatformCertificateInfo::decode):
* Shared/qt/QtNetworkReplyData.cpp:
(WebKit::QtNetworkReplyData::decode):
* Shared/qt/QtNetworkReplyData.h:
(QtNetworkReplyData):
* Shared/qt/QtNetworkRequestData.cpp:
(WebKit::QtNetworkRequestData::decode):
* Shared/qt/QtNetworkRequestData.h:
(QtNetworkRequestData):
* Shared/qt/WebCoreArgumentCodersQt.cpp:
(CoreIPC::::decodePlatformData):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141632 268f45cc-cd09-0410-ab3c-d52691b4dbfc