[cleanup] Use backticks instead of pipes in comments

Change wrapper for function, class, or variable names in comments
from  pipes to backticks in chrome/browser/printing folder.
Using backticks instead of pipes, because then Code Search
will be able to automatically make links [1] from them.

[1]  http://go/cstyle#function_declarations

Change-Id: I323c734d37d2d22ad6f85273ad6b9ac0bca61698
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3408333
Reviewed-by: Alan Screen <[email protected]>
Commit-Queue: Daisy Doan <[email protected]>
Cr-Commit-Position: refs/heads/main@{#962188}
diff --git a/chrome/browser/printing/print_view_manager.h b/chrome/browser/printing/print_view_manager.h
index 85a6981..8ce43d81 100644
--- a/chrome/browser/printing/print_view_manager.h
+++ b/chrome/browser/printing/print_view_manager.h
@@ -34,7 +34,7 @@
 
   // Same as PrintNow(), but for the case where a user prints with the system
   // dialog from print preview.
-  // |dialog_shown_callback| is called when the print dialog is shown.
+  // `dialog_shown_callback` is called when the print dialog is shown.
   bool PrintForSystemDialogNow(base::OnceClosure dialog_shown_callback);
 
   // Same as PrintNow(), but for the case where a user press "ctrl+shift+p" to
@@ -109,7 +109,7 @@
 
   // Helper method for ShowScriptedPrintPreview(), called from
   // RejectPrintPreviewRequestIfRestricted(). Based on value of
-  // |should_proceed|, continues to show the print preview or cancels it.
+  // `should_proceed`, continues to show the print preview or cancels it.
   void OnScriptedPrintPreviewCallback(bool source_is_modifiable,
                                       int render_process_id,
                                       int render_frame_id,
@@ -117,7 +117,7 @@
 
   // Helper method for RequestPrintPreview(), called from
   // RejectPrintPreviewRequestIfRestricted(). Based on value of
-  // |should_proceed|, continues to show the print preview or cancels it.
+  // `should_proceed`, continues to show the print preview or cancels it.
   void OnRequestPrintPreviewCallback(mojom::RequestPrintPreviewParamsPtr params,
                                      int render_process_id,
                                      int render_frame_id,
@@ -126,7 +126,7 @@
   void MaybeUnblockScriptedPreviewRPH();
 
   // Checks whether printing is currently restricted and aborts print preview if
-  // needed. Since this check is performed asynchronously, invokes |callback|
+  // needed. Since this check is performed asynchronously, invokes `callback`
   // with an indicator whether to proceed or not.
   // Virtual to allow tests to override.
   virtual void RejectPrintPreviewRequestIfRestricted(
@@ -151,13 +151,13 @@
   PrintPreviewState print_preview_state_ = NOT_PREVIEWING;
 
   // The current RFH that is print previewing. It should be a nullptr when
-  // |print_preview_state_| is NOT_PREVIEWING.
+  // `print_preview_state_` is NOT_PREVIEWING.
   raw_ptr<content::RenderFrameHost> print_preview_rfh_ = nullptr;
 
   // Keeps track of the pending callback during scripted print preview.
   raw_ptr<content::RenderProcessHost> scripted_print_preview_rph_ = nullptr;
 
-  // True if |scripted_print_preview_rph_| needs to be unblocked.
+  // True if `scripted_print_preview_rph_` needs to be unblocked.
   bool scripted_print_preview_rph_set_blocked_ = false;
 
   // Indicates whether we're switching from print preview to system dialog. This