alloy: Fix printing of PDF viewer (see issue #3047)

Match the logic for printing::StartPrint() used by Chrome.

libcef/browser/alloy/browser_platform_delegate_alloy.cc

@@ -17,6 +17,7 @@
 
 #include "base/logging.h"
 #include "chrome/browser/printing/print_view_manager.h"
+#include "chrome/browser/printing/print_view_manager_common.h"
 #include "chrome/browser/ui/prefs/prefs_tab_helper.h"
 #include "components/find_in_page/find_tab_helper.h"
 #include "components/find_in_page/find_types.h"
@@ -26,6 +27,7 @@
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host.h"
 #include "extensions/browser/process_manager.h"
+#include "pdf/pdf_features.h"
 #include "printing/mojom/print.mojom.h"
 #include "third_party/blink/public/mojom/frame/find_in_page.mojom.h"
 
@@ -341,33 +343,30 @@ void CefBrowserPlatformDelegateAlloy::SetAccessibilityState(
 bool CefBrowserPlatformDelegateAlloy::IsPrintPreviewSupported() const {
   REQUIRE_ALLOY_RUNTIME();
 
-  auto actionable_contents = GetActionableWebContents();
-  if (!actionable_contents)
-    return false;
-
-  auto cef_browser_context = CefBrowserContext::FromBrowserContext(
-      actionable_contents->GetBrowserContext());
-  if (!cef_browser_context->IsPrintPreviewSupported()) {
-    return false;
-  }
-
   // Print preview is not currently supported with OSR.
-  return !IsWindowless();
+  if (IsWindowless())
+    return false;
+
+  auto cef_browser_context =
+      CefBrowserContext::FromBrowserContext(web_contents_->GetBrowserContext());
+  return cef_browser_context->IsPrintPreviewSupported();
 }
 
 void CefBrowserPlatformDelegateAlloy::Print() {
   REQUIRE_ALLOY_RUNTIME();
 
-  auto actionable_contents = GetActionableWebContents();
-  if (!actionable_contents)
+  auto contents_to_use = printing::GetWebContentsToUse(web_contents_);
+  if (!contents_to_use)
     return;
 
-  auto rfh = actionable_contents->GetMainFrame();
+  auto rfh_to_use = printing::GetRenderFrameHostToUse(contents_to_use);
+  if (!rfh_to_use)
+    return;
 
   if (IsPrintPreviewSupported()) {
-    GetPrintViewManager(actionable_contents)->PrintPreviewNow(rfh, false);
+    GetPrintViewManager(contents_to_use)->PrintPreviewNow(rfh_to_use, false);
   } else {
-    GetPrintViewManager(actionable_contents)->PrintNow(rfh);
+    GetPrintViewManager(contents_to_use)->PrintNow(rfh_to_use);
   }
 }
 
@@ -377,17 +376,22 @@ void CefBrowserPlatformDelegateAlloy::PrintToPDF(
     CefRefPtr<CefPdfPrintCallback> callback) {
   REQUIRE_ALLOY_RUNTIME();
 
-  content::WebContents* actionable_contents = GetActionableWebContents();
-  if (!actionable_contents)
+  auto contents_to_use = printing::GetWebContentsToUse(web_contents_);
+  if (!contents_to_use)
     return;
+
+  auto rfh_to_use = printing::GetRenderFrameHostToUse(contents_to_use);
+  if (!rfh_to_use)
+    return;
+
   printing::CefPrintViewManager::PdfPrintCallback pdf_callback;
   if (callback.get()) {
     pdf_callback = base::BindOnce(&CefPdfPrintCallback::OnPdfPrintFinished,
                                   callback.get(), path);
   }
-  GetPrintViewManager(actionable_contents)
-      ->PrintToPDF(actionable_contents->GetMainFrame(), base::FilePath(path),
-                   settings, std::move(pdf_callback));
+  GetPrintViewManager(contents_to_use)
+      ->PrintToPDF(rfh_to_use, base::FilePath(path), settings,
+                   std::move(pdf_callback));
 }
 
 void CefBrowserPlatformDelegateAlloy::Find(const CefString& searchText,
@@ -442,17 +446,6 @@ CefBrowserPlatformDelegateAlloy::GetBoundsChangedCallback() {
   return base::RepeatingClosure();
 }
 
-content::WebContents*
-CefBrowserPlatformDelegateAlloy::GetActionableWebContents() const {
-  if (web_contents_ && extensions::ExtensionsEnabled()) {
-    content::WebContents* guest_contents =
-        extensions::GetFullPageGuestForOwnerContents(web_contents_);
-    if (guest_contents)
-      return guest_contents;
-  }
-  return web_contents_;
-}
-
 void CefBrowserPlatformDelegateAlloy::SetOwnedWebContents(
     content::WebContents* owned_contents) {
   DCHECK(primary_);

libcef/browser/alloy/browser_platform_delegate_alloy.h

@@ -81,12 +81,6 @@ class CefBrowserPlatformDelegateAlloy : public CefBrowserPlatformDelegate {
 
   base::RepeatingClosure GetBoundsChangedCallback();
 
-  // Returns the WebContents most likely to handle an action. If extensions are
-  // enabled and this browser has a full-page guest (for example, a full-page
-  // PDF viewer extension) then the guest's WebContents will be returned.
-  // Otherwise, the browser's WebContents will be returned.
-  content::WebContents* GetActionableWebContents() const;
-
   // Called from BrowserPlatformDelegateNative::set_windowless_handler().
   void set_as_secondary() { primary_ = false; }
 

libcef/browser/extensions/browser_extensions_util.cc

@@ -15,7 +15,6 @@
 
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/printing/print_preview_dialog_controller.h"
-#include "content/browser/browser_plugin/browser_plugin_embedder.h"
 #include "content/browser/browser_plugin/browser_plugin_guest.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/browser_context.h"
@@ -36,21 +35,6 @@ bool InsertWebContents(std::vector<content::WebContents*>* vector,
 
 }  // namespace
 
-content::WebContents* GetFullPageGuestForOwnerContents(
-    content::WebContents* owner) {
-  content::WebContentsImpl* owner_impl =
-      static_cast<content::WebContentsImpl*>(owner);
-  content::BrowserPluginEmbedder* plugin_embedder =
-      owner_impl->GetBrowserPluginEmbedder();
-  if (plugin_embedder) {
-    content::BrowserPluginGuest* plugin_guest =
-        plugin_embedder->GetFullPageGuest();
-    if (plugin_guest)
-      return plugin_guest->web_contents();
-  }
-  return nullptr;
-}
-
 void GetAllGuestsForOwnerContents(content::WebContents* owner,
                                   std::vector<content::WebContents*>* guests) {
   content::BrowserPluginGuestManager* plugin_guest_manager =

libcef/browser/extensions/browser_extensions_util.h

@@ -26,10 +26,6 @@ namespace extensions {
 
 class Extension;
 
-// Returns the full-page guest WebContents for the specified |owner|, if any.
-content::WebContents* GetFullPageGuestForOwnerContents(
-    content::WebContents* owner);
-
 // Populates |guests| with all guest WebContents with the specified |owner|.
 void GetAllGuestsForOwnerContents(content::WebContents* owner,
                                   std::vector<content::WebContents*>* guests);

patch/patch.cfg

@@ -333,6 +333,11 @@ patches = [
     # https://bitbucket.org/chromiumembedded/cef/issues/2196
     'name': 'printing_context_2196',
   },
+  {
+    # Expose the printing::GetRenderFrameHostToUse() method.
+    # https://bitbucket.org/chromiumembedded/cef/issues/3057
+    'name': 'printing_pdf_3047',
+  },
   {
     # Windows: Remove llvmlibthin as the combine_libs.py can't handle those.
     # https://bitbucket.org/chromiumembedded/cef/issues/2470

patch/patches/printing_pdf_3047.patch

@@ -0,0 +1,37 @@
+diff --git chrome/browser/printing/print_view_manager_common.cc chrome/browser/printing/print_view_manager_common.cc
+index fe86f14eeacb8..41858f4357f8e 100644
+--- chrome/browser/printing/print_view_manager_common.cc
++++ chrome/browser/printing/print_view_manager_common.cc
+@@ -53,6 +53,8 @@ bool StoreFullPagePlugin(content::WebContents** result,
+ }
+ #endif  // BUILDFLAG(ENABLE_EXTENSIONS)
+ 
++}  // namespace
++
+ // Pick the right RenderFrameHost based on the WebContents.
+ content::RenderFrameHost* GetRenderFrameHostToUse(
+     content::WebContents* contents) {
+@@ -68,8 +70,6 @@ content::RenderFrameHost* GetRenderFrameHostToUse(
+   return contents->GetMainFrame();
+ }
+ 
+-}  // namespace
+-
+ void StartPrint(
+     content::WebContents* contents,
+     mojo::PendingAssociatedRemote<mojom::PrintRenderer> print_renderer,
+diff --git chrome/browser/printing/print_view_manager_common.h chrome/browser/printing/print_view_manager_common.h
+index bf67ddba35b34..7f4dcc216bbb4 100644
+--- chrome/browser/printing/print_view_manager_common.h
++++ chrome/browser/printing/print_view_manager_common.h
+@@ -36,6 +36,10 @@ content::RenderFrameHost* GetFrameToPrint(content::WebContents* contents);
+ // guest's WebContents instead.
+ content::WebContents* GetWebContentsToUse(content::WebContents* contents);
+ 
++// Pick the right RenderFrameHost based on the WebContents.
++content::RenderFrameHost* GetRenderFrameHostToUse(
++    content::WebContents* contents);
++
+ }  // namespace printing
+ 
+ #endif  // CHROME_BROWSER_PRINTING_PRINT_VIEW_MANAGER_COMMON_H_