[unseasoned-pdf] Print the correct RenderFrameHost using one WebContents

GetRenderFrameHostToUse() took two WebContents to apply its heuristics
for printing the right RenderFrameHost. The function assumed the
WebContents to use were that of a full page plugin if and only if it was
different than the "owning" WebContents.

That logic was faulty when the "owning" WebContents was that of a full
page plugin already, which is possible when the print operation is
targeted to the plugin's WebContents from the context menu.

Instead, directly check whether the WebContents to use is a full page
plugin, and dispose of the need to check using the "owning" WebContents.

Fixed: 1259307
Change-Id: I36ee95f2385a457e18db43a24f853f9fd1bdbc1d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3219937
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Daniel Hosseinian <dhoss@chromium.org>
Cr-Commit-Position: refs/heads/main@{#931850}

chrome/browser/pdf/pdf_extension_test.cc

@@ -138,6 +138,7 @@
 #include "chrome/browser/ui/browser_commands.h"
 #if BUILDFLAG(ENABLE_PRINT_PREVIEW)
 #include "chrome/browser/printing/print_view_manager.h"
+#include "ui/base/ui_base_types.h"
 #else
 #include "chrome/browser/printing/print_view_manager_basic.h"
 #endif
@@ -1633,6 +1634,21 @@ IN_PROC_BROWSER_TEST_P(PDFExtensionTest, PrintCommand) {
   chrome::Print(browser());
   print_observer.WaitForPrintPreview();
 }
+
+IN_PROC_BROWSER_TEST_P(PDFExtensionTest, ContextMenuPrintCommand) {
+  content::WebContents* guest_contents =
+      LoadPdfGetGuestContents(embedded_test_server()->GetURL("/pdf/test.pdf"));
+  content::RenderFrameHost* plugin_frame = GetPluginFrame(guest_contents);
+  ASSERT_TRUE(plugin_frame);
+
+  // Executes the print command as soon as the context menu is shown.
+  ContextMenuNotificationObserver context_menu_observer(IDC_PRINT);
+
+  PrintObserver print_observer(guest_contents, plugin_frame);
+  guest_contents->GetMainFrame()->GetRenderWidgetHost()->ShowContextMenuAtPoint(
+      {1, 1}, ui::MENU_SOURCE_MOUSE);
+  print_observer.WaitForPrintPreview();
+}
 #endif  // BUILDFLAG(ENABLE_PRINT_PREVIEW)
 #endif  // BUILDFLAG(ENABLE_PRINTING)
 

chrome/browser/printing/print_view_manager_common.cc

@@ -28,35 +28,44 @@
 namespace printing {
 
 namespace {
+// Returns true if `contents` is a full page MimeHandlerViewGuest plugin.
+bool IsFullPagePlugin(content::WebContents* contents) {
 #if BUILDFLAG(ENABLE_EXTENSIONS)
-// Stores |guest_contents| in |result| and returns true if |guest_contents| is a
-// full page MimeHandlerViewGuest plugin. Otherwise, returns false.
+  auto* guest_view =
+      extensions::MimeHandlerViewGuest::FromWebContents(contents);
+  if (guest_view && guest_view->is_full_page_plugin())
+    return true;
+#endif
+  return false;
+}
+
+#if BUILDFLAG(ENABLE_EXTENSIONS)
+// Stores `guest_contents` in `result` and returns true if
+// `IsFullPagePlugin(guest_contents)`. Otherwise, returns false and `result`
+// remains unchanged.
 bool StoreFullPagePlugin(content::WebContents** result,
                          content::WebContents* guest_contents) {
-  auto* guest_view =
-      extensions::MimeHandlerViewGuest::FromWebContents(guest_contents);
-  if (guest_view && guest_view->is_full_page_plugin()) {
+  if (IsFullPagePlugin(guest_contents)) {
     *result = guest_contents;
     return true;
   }
   return false;
 }
 #endif  // BUILDFLAG(ENABLE_EXTENSIONS)
 
-// Pick the right RenderFrameHost based on the WebContentses.
+// Pick the right RenderFrameHost based on the WebContents.
 content::RenderFrameHost* GetRenderFrameHostToUse(
-    content::WebContents* original_contents,
-    content::WebContents* contents_to_use) {
-  if (original_contents == contents_to_use)
-    return GetFrameToPrint(contents_to_use);
+    content::WebContents* contents) {
+  if (!IsFullPagePlugin(contents))
+    return GetFrameToPrint(contents);
 
 #if BUILDFLAG(ENABLE_PDF)
   content::RenderFrameHost* pdf_rfh =
-      pdf_frame_util::FindPdfChildFrame(contents_to_use->GetMainFrame());
+      pdf_frame_util::FindPdfChildFrame(contents->GetMainFrame());
   if (pdf_rfh)
     return pdf_rfh;
 #endif
-  return contents_to_use->GetMainFrame();
+  return contents->GetMainFrame();
 }
 
 }  // namespace
@@ -79,7 +88,7 @@ void StartPrint(
     return;
 
   content::RenderFrameHost* rfh_to_use =
-      GetRenderFrameHostToUse(contents, contents_to_use);
+      GetRenderFrameHostToUse(contents_to_use);
   if (!rfh_to_use)
     return;
 
@@ -107,7 +116,7 @@ void StartBasicPrint(content::WebContents* contents) {
     return;
 
   content::RenderFrameHost* rfh_to_use =
-      GetRenderFrameHostToUse(contents, contents_to_use);
+      GetRenderFrameHostToUse(contents_to_use);
   if (!rfh_to_use)
     return;