Avoid calling member fcn after possible delf-deletion.

If RemoveFrameContainerForReason() successfully removes a frame, the
|this| pointer will become invalid. This CL removes a member function
invocation that occurs when |this| might be invalid.

Bug: 1088187
Change-Id: I5abc6f03ff326ebbcfb696205deb5058ec977c78
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2250580
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780009}

extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container_manager.cc

@@ -270,6 +270,8 @@ void MimeHandlerViewContainerManager::RemoveFrameContainerForReason(
     bool retain_manager) {
   if (!RemoveFrameContainer(frame_container, retain_manager))
     return;
+  // At this point |this| may be invalid, but it's still OK to call
+  // RecordInteraction() as it's declared static.
   RecordInteraction(event);
 }
 
@@ -298,6 +300,7 @@ void MimeHandlerViewContainerManager::SetShowBeforeUnloadDialog(
   std::move(callback).Run();
 }
 
+// static
 void MimeHandlerViewContainerManager::RecordInteraction(UMAType type) {
   base::UmaHistogramEnumeration(MimeHandlerViewUMATypes::kUMAName, type);
 }

extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container_manager.h

@@ -111,6 +111,9 @@ class MimeHandlerViewContainerManager
                const GURL& resource_url) override;
 
  private:
+  // Static so it can be called after self-deletion.
+  static void RecordInteraction(MimeHandlerViewUMATypes::Type type);
+
   // PostMessageSupport::Delegate overrides.
   blink::WebLocalFrame* GetSourceFrame() override;
   blink::WebFrame* GetTargetFrame() override;
@@ -126,8 +129,6 @@ class MimeHandlerViewContainerManager
       bool show_dialog,
       SetShowBeforeUnloadDialogCallback callback) override;
 
-  void RecordInteraction(MimeHandlerViewUMATypes::Type type);
-
   // Returns true if the |element| is managed by
   // MimeHandlerViewContainerManager; this would be the element that is added by
   // the HTML string injected at MimeHandlerViewAttachHelper.