Don't depend on PyQt5.QtQuickWidgets to get RWHV

Some distributions (at least FreeBSD) don't package that module, so let's not
rely on it.

doc/changelog.asciidoc

@@ -55,6 +55,9 @@ Added
 Changed
 ~~~~~~~
 
+- In v1.3.2 a dependency on the `PyQt5.QtQuickWidgets` module was accidentally
+  introduced. Since that module isn't packaged everywhere, it's been removed
+  again.
 - The Windows/macOS releases now bundle Qt 5.11.1 which is based on
   Chromium 65.0.3325.151 with security fixes up to Chromium 67.0.3396.87.
 - New short flags for commandline arguments: `-B` and `-T` for `--basedir` and

qutebrowser/browser/webengine/webview.py

@@ -22,7 +22,7 @@
 import sip
 from PyQt5.QtCore import pyqtSignal, pyqtSlot, QUrl, PYQT_VERSION
 from PyQt5.QtGui import QPalette
-from PyQt5.QtQuickWidgets import QQuickWidget
+from PyQt5.QtWidgets import QWidget
 from PyQt5.QtWebEngineWidgets import (QWebEngineView, QWebEnginePage,
                                       QWebEngineScript)
 
@@ -71,10 +71,10 @@ class WebEngineView(QWebEngineView):
             if proxy is not None:
                 return proxy
 
-        # This should only find the RenderWidgetHostViewQtDelegateWidget,
-        # but not e.g. a QMenu
-        children = [c for c in self.findChildren(QQuickWidget)
-                    if c.isVisible()]
+        # We don't want e.g. a QMenu.
+        rwhv_class = 'QtWebEngineCore::RenderWidgetHostViewQtDelegateWidget'
+        children = [c for c in self.findChildren(QWidget)
+                    if c.isVisible() and c.inherits(rwhv_class)]
 
         log.webview.debug("Found possibly lost focusProxy: {}"
                           .format(children))

tests/end2end/fixtures/quteprocess.py

@@ -361,9 +361,6 @@ class QuteProc(testprocess.Process):
             "Focus object changed: "
             "<qutebrowser.browser.webengine.webview.WebEngineView object "
             "at *>",
-            # Qt >= 5.11 with workarounds
-            "Focus object changed: "
-            "<PyQt5.QtQuickWidgets.QQuickWidget object at *>",
         ]
 
         if (log_line.category == 'ipc' and