[MPArch] Migrate GuestView lookup in print_view_manager_common.cc

Uses the RenderFrameHost based lookup method for GuestView instead of
the one based in WebContents. This CL is part of the pre-work to
migrate GuestViews to MPArch.

Bug: 1362569
Change-Id: I0f68f553947b0ce6c938248807927f4e81b1ff78
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3948865
Reviewed-by: Kevin McNee <mcnee@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Antia Puentes <apuentes@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1060081}

diff --git a/chrome/browser/printing/print_view_manager_common.h b/chrome/browser/printing/print_view_manager_common.h
index c8ba345..cc7b277 100644
--- a/chrome/browser/printing/print_view_manager_common.h
+++ b/chrome/browser/printing/print_view_manager_common.h

@@ -33,8 +33,8 @@
 content::RenderFrameHost* GetFrameToPrint(content::WebContents* contents);
 
 // If we have a single full-page embedded mime handler view guest, print the
-// guest's WebContents instead.
-content::WebContents* GetWebContentsToUse(content::WebContents* contents);
+// guest view instead.
+content::RenderFrameHost* GetFullPagePlugin(content::WebContents* contents);
 
 }  // namespace printing