[Safer CPP] Address UncheckedLocalVars warnings in PDFPluginBase.mm

https://bugs.webkit.org/show_bug.cgi?id=290286
rdar://147690815

Reviewed by Chris Dumez.

* Source/WebKit/SaferCPPExpectations/UncheckedLocalVarsCheckerExpectations:
* Source/WebKit/WebProcess/Plugins/PDF/PDFPluginBase.mm:
(WebKit::PDFPluginBase::showContextMenuAtPoint):

Canonical link: https://commits.webkit.org/292570@main

Author: aprotyas

Source/WebKit/SaferCPPExpectations/UncheckedLocalVarsCheckerExpectations

@@ -1,7 +1,6 @@
 WebProcess/InjectedBundle/DOM/InjectedBundleNodeHandle.cpp
 WebProcess/InjectedBundle/DOM/InjectedBundleRangeHandle.cpp
 WebProcess/InjectedBundle/InjectedBundleHitTestResult.cpp
-WebProcess/Plugins/PDF/PDFPluginBase.mm
 WebProcess/WebPage/DrawingArea.cpp
 WebProcess/WebPage/RemoteLayerTree/GraphicsLayerCARemote.mm
 WebProcess/WebPage/RemoteLayerTree/RemoteScrollingCoordinator.mm

Source/WebKit/WebProcess/Plugins/PDF/PDFPluginBase.mm

@@ -1227,7 +1227,7 @@
 
 bool PDFPluginBase::showContextMenuAtPoint(const IntPoint& point)
 {
-    auto* frameView = m_frame ? m_frame->coreLocalFrame()->view() : nullptr;
+    RefPtr frameView = m_frame ? m_frame->coreLocalFrame()->view() : nullptr;
     if (!frameView)
         return false;
     IntPoint contentsPoint = frameView->contentsToRootView(point);