diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 548adda18ef6..3b5f81b74dc4 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,13 @@
+2015-07-27  Carlos Garcia Campos  <cgarcia@igalia.com>
+
+        [GTK] Pass a GstInstallPluginsContext to gst_install_plugins_async
+        https://bugs.webkit.org/show_bug.cgi?id=147103
+
+        Reviewed by Philippe Normand.
+
+        * platform/graphics/gstreamer/GUniquePtrGStreamer.h: Allow to use
+        GUniquePtr with GstInstallPluginsContext.
+
 2015-07-24  Carlos Garcia Campos  <cgarcia@igalia.com>
 
         [GStreamer] Crashes during plugin installation
diff --git a/Source/WebCore/platform/graphics/gstreamer/GUniquePtrGStreamer.h b/Source/WebCore/platform/graphics/gstreamer/GUniquePtrGStreamer.h
index c4d12b5b69aa..2c5ea6dc6d17 100644
--- a/Source/WebCore/platform/graphics/gstreamer/GUniquePtrGStreamer.h
+++ b/Source/WebCore/platform/graphics/gstreamer/GUniquePtrGStreamer.h
@@ -22,11 +22,13 @@
 #if USE(GSTREAMER)
 
 #include <gst/gststructure.h>
+#include <gst/pbutils/install-plugins.h>
 #include <wtf/gobject/GUniquePtr.h>
 
 namespace WTF {
 
 WTF_DEFINE_GPTR_DELETER(GstStructure, gst_structure_free)
+WTF_DEFINE_GPTR_DELETER(GstInstallPluginsContext, gst_install_plugins_context_free)
 
 }
 
diff --git a/Source/WebKit2/ChangeLog b/Source/WebKit2/ChangeLog
index f94cc3309842..0677740be0c7 100644
--- a/Source/WebKit2/ChangeLog
+++ b/Source/WebKit2/ChangeLog
@@ -1,3 +1,27 @@
+2015-07-27  Carlos Garcia Campos  <cgarcia@igalia.com>
+
+        [GTK] Pass a GstInstallPluginsContext to gst_install_plugins_async
+        https://bugs.webkit.org/show_bug.cgi?id=147103
+
+        Reviewed by Philippe Normand.
+
+        This allows PackageKit to properly position the window and make it
+        transient to the web view window.
+
+        * UIProcess/API/gtk/PageClientImpl.cpp:
+        (WebKit::PageClientImpl::setCursor): Disambiguate Cursor now that
+        we include gtkx.h.
+        (WebKit::PageClientImpl::createGstInstallPluginsContext): Create a
+        new GstInstallPluginsContext and set the web view window XID when
+        running on X11.
+        * UIProcess/API/gtk/PageClientImpl.h:
+        * UIProcess/PageClient.h:
+        * UIProcess/efl/WebViewEfl.h:
+        * UIProcess/gstreamer/WebPageProxyGStreamer.cpp:
+        (WebKit::WebPageProxy::requestInstallMissingMediaPlugins): Use
+        PageClient::createGstInstallPluginsContext() to create a new
+        GstInstallPluginsContext and pass it to gst_install_plugins_async().
+
 2015-07-24  Anders Carlsson  <andersca@apple.com>
 
         Networking process crash in NetworkConnectionToWebProcess::convertMainResourceLoadToDownload while attempting to download a blob
diff --git a/Source/WebKit2/UIProcess/API/gtk/PageClientImpl.cpp b/Source/WebKit2/UIProcess/API/gtk/PageClientImpl.cpp
index be53871cbdb1..831305021a63 100644
--- a/Source/WebKit2/UIProcess/API/gtk/PageClientImpl.cpp
+++ b/Source/WebKit2/UIProcess/API/gtk/PageClientImpl.cpp
@@ -47,6 +47,11 @@
 #include <wtf/text/CString.h>
 #include <wtf/text/WTFString.h>
 
+#if PLATFORM(X11)
+#include <gdk/gdkx.h>
+#undef KeyPress
+#endif
+
 using namespace WebCore;
 
 namespace WebKit {
@@ -132,7 +137,7 @@ void PageClientImpl::toolTipChanged(const String&, const String& newToolTip)
     webkitWebViewBaseSetTooltipText(WEBKIT_WEB_VIEW_BASE(m_viewWidget), newToolTip.utf8().data());
 }
 
-void PageClientImpl::setCursor(const Cursor& cursor)
+void PageClientImpl::setCursor(const WebCore::Cursor& cursor)
 {
     if (!gtk_widget_get_realized(m_viewWidget))
         return;
@@ -427,4 +432,19 @@ void PageClientImpl::didSameDocumentNavigationForMainFrame(SameDocumentNavigatio
 {
 }
 
+#if ENABLE(VIDEO)
+GUniquePtr<GstInstallPluginsContext> PageClientImpl::createGstInstallPluginsContext()
+{
+#if PLATFORM(X11)
+    if (GDK_IS_X11_DISPLAY(gdk_display_manager_get_default_display(gdk_display_manager_get()))) {
+        GUniquePtr<GstInstallPluginsContext> context(gst_install_plugins_context_new());
+        gst_install_plugins_context_set_xid(context.get(), GDK_WINDOW_XID(gtk_widget_get_window(m_viewWidget)));
+        return context;
+    }
+#endif
+
+    return nullptr;
+}
+#endif
+
 } // namespace WebKit
diff --git a/Source/WebKit2/UIProcess/API/gtk/PageClientImpl.h b/Source/WebKit2/UIProcess/API/gtk/PageClientImpl.h
index 6b2047bb3426..67b6447c783a 100644
--- a/Source/WebKit2/UIProcess/API/gtk/PageClientImpl.h
+++ b/Source/WebKit2/UIProcess/API/gtk/PageClientImpl.h
@@ -136,6 +136,10 @@ class PageClientImpl : public PageClient
 
     virtual void doneWithTouchEvent(const NativeWebTouchEvent&, bool wasEventHandled) override;
 
+#if ENABLE(VIDEO)
+    virtual GUniquePtr<GstInstallPluginsContext> createGstInstallPluginsContext() override;
+#endif
+
     // Members of PageClientImpl class
     GtkWidget* m_viewWidget;
     DefaultUndoController m_undoController;
diff --git a/Source/WebKit2/UIProcess/PageClient.h b/Source/WebKit2/UIProcess/PageClient.h
index b27fe36e5630..e3f8b10ddfbe 100644
--- a/Source/WebKit2/UIProcess/PageClient.h
+++ b/Source/WebKit2/UIProcess/PageClient.h
@@ -34,6 +34,10 @@
 #include <WebCore/EditorClient.h>
 #include <wtf/Forward.h>
 
+#if ENABLE(VIDEO) && USE(GSTREAMER)
+#include <WebCore/GUniquePtrGStreamer.h>
+#endif
+
 #if PLATFORM(COCOA)
 #include "PluginComplexTextInputState.h"
 
@@ -315,6 +319,10 @@ class PageClient {
 #if PLATFORM(MAC)
     virtual void didPerformActionMenuHitTest(const ActionMenuHitTestResult&, bool forImmediateAction, API::Object*) = 0;
 #endif
+
+#if ENABLE(VIDEO) && USE(GSTREAMER)
+    virtual GUniquePtr<GstInstallPluginsContext> createGstInstallPluginsContext() = 0;
+#endif
 };
 
 } // namespace WebKit
diff --git a/Source/WebKit2/UIProcess/gstreamer/WebPageProxyGStreamer.cpp b/Source/WebKit2/UIProcess/gstreamer/WebPageProxyGStreamer.cpp
index 0739fbbd8db0..3013482a5149 100644
--- a/Source/WebKit2/UIProcess/gstreamer/WebPageProxyGStreamer.cpp
+++ b/Source/WebKit2/UIProcess/gstreamer/WebPageProxyGStreamer.cpp
@@ -28,8 +28,8 @@
 
 #if ENABLE(VIDEO) && USE(GSTREAMER)
 
+#include "PageClient.h"
 #include "WebPageMessages.h"
-#include <gst/pbutils/install-plugins.h>
 
 namespace WebKit {
 
@@ -38,8 +38,8 @@ void WebPageProxy::requestInstallMissingMediaPlugins(const String& details)
     CString detail = details.utf8();
     const char* detailArray[2] = { detail.data(), nullptr };
     ref();
-    // FIXME: Use a proper GstInstallPluginsContext instead of nullptr.
-    GstInstallPluginsReturn result = gst_install_plugins_async(detailArray, nullptr, [](GstInstallPluginsReturn result, gpointer userData) {
+    GUniquePtr<GstInstallPluginsContext> context = m_pageClient.createGstInstallPluginsContext();
+    GstInstallPluginsReturn result = gst_install_plugins_async(detailArray, context.get(), [](GstInstallPluginsReturn result, gpointer userData) {
         RefPtr<WebPageProxy> page = adoptRef(static_cast<WebPageProxy*>(userData));
         if (page->isValid())
             page->send(Messages::WebPage::DidEndRequestInstallMissingMediaPlugins(static_cast<uint32_t>(result)));