[GTK] Remove support for GTK2 plugins

[GTK] Remove support for GTK2 plugins
https://bugs.webkit.org/show_bug.cgi?id=199065

Reviewed by Sergio Villar Senin.

.:

* Source/cmake/FindGDK2.cmake: Removed.
* Source/cmake/FindGTK2.cmake: Removed.
* Source/cmake/OptionsGTK.cmake:

PerformanceTests:

* StitchMarker/wtf/Platform.h:

Source/WebCore:

* PlatformGTK.cmake:
* SourcesGTK.txt:
* SourcesWPE.txt:
* platform/FreeType.cmake:
* platform/SourcesGLib.txt:
* platform/graphics/Color.h:
* platform/graphics/PlatformDisplay.cpp:
(WebCore::PlatformDisplay::createPlatformDisplay):
* platform/graphics/gtk/ColorGtk.cpp:
(WebCore::Color::operator GdkRGBA const):
* platform/graphics/gtk/DisplayRefreshMonitorGtk.cpp:
(WebCore::onFrameClockUpdate):
(WebCore::DisplayRefreshMonitorGtk::requestRefreshCallback):
* platform/graphics/gtk/DisplayRefreshMonitorGtk.h:
(WebCore::DisplayRefreshMonitorGtk::create):
* platform/graphics/gtk/GdkCairoUtilities.cpp:
* platform/gtk/GRefPtrGtk.cpp:
* platform/gtk/GRefPtrGtk.h:
* platform/gtk/GtkVersioning.c: Removed.
* platform/gtk/GtkVersioning.h: Removed.
* platform/gtk/PasteboardHelper.cpp:
(WebCore::PasteboardHelper::getClipboardContents):
* platform/gtk/PlatformKeyboardEventGtk.cpp:
(WebCore::modifiersForGdkKeyEvent):
(WebCore::PlatformKeyboardEvent::PlatformKeyboardEvent):
* platform/gtk/PlatformMouseEventGtk.cpp:
(WebCore::PlatformMouseEvent::PlatformMouseEvent):
* platform/gtk/PlatformScreenGtk.cpp:
(WebCore::screenIsTouchPrimaryInputDevice):
* platform/gtk/PlatformWheelEventGtk.cpp:
(WebCore::PlatformWheelEvent::PlatformWheelEvent):
* platform/gtk/ScrollbarThemeGtk.cpp:
* platform/gtk/ScrollbarThemeGtk.h:
* platform/gtk/WidgetGtk.cpp:
* rendering/RenderThemeGtk.cpp:
* rendering/RenderThemeGtk.h:

Source/WebKit:

* PlatformGTK.cmake:
* Shared/Plugins/Netscape/NetscapePluginModule.cpp:
(WebKit::moduleMixesGtkSymbols):
* Shared/Plugins/Netscape/unix/NetscapePluginModuleUnix.cpp:
(WebKit::NetscapePluginModule::getPluginInfo):
* Shared/Plugins/PluginModuleInfo.h:
* Shared/gtk/WebEventFactory.cpp:
(WebKit::isGdkKeyCodeFromKeyPad):
(WebKit::buttonForEvent):
(WebKit::WebEventFactory::createWebMouseEvent):
(WebKit::WebEventFactory::createWebWheelEvent):
(WebKit::WebEventFactory::createWebKeyboardEvent):
(WebKit::WebEventFactory::createWebTouchEvent):
* SourcesGTK.txt:
* UIProcess/API/gtk/WebKitWebViewBase.cpp:
* UIProcess/Launcher/glib/ProcessLauncherGLib.cpp:
(WebKit::ProcessLauncher::launchProcess):
* UIProcess/Plugins/PluginProcessProxy.h:
* UIProcess/Plugins/gtk/PluginInfoCache.cpp:
(WebKit::PluginInfoCache::getPluginInfo):
(WebKit::PluginInfoCache::updatePluginInfo):
* UIProcess/Plugins/unix/PluginInfoStoreUnix.cpp:
(WebKit::PluginInfoStore::getPluginInfo):
* UIProcess/Plugins/unix/PluginProcessProxyUnix.cpp:
(WebKit::PluginProcessProxy::platformGetLaunchOptionsWithAttributes):
(WebKit::PluginProcessProxy::scanPlugin):
* WebProcess/Plugins/Netscape/x11/NetscapePluginX11.cpp:

Source/WTF:

* wtf/Platform.h:
* wtf/glib/GTypedefs.h:

Tools:

* EWSTools/ubuntu-ews-packages:
* TestWebKitAPI/PlatformGTK.cmake:
* WebKitTestRunner/PlatformGTK.cmake:
* flatpak/org.webkit.GTK.yaml:
* gtk/install-dependencies:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@246632 268f45cc-cd09-0410-ab3c-d52691b4dbfc