Make Edit>Speech>Speak Selection work for PDFs on Mac

extensions/browser/guest_view/guest_view_manager.cc

Index: extensions/browser/guest_view/guest_view_manager.cc
diff --git a/extensions/browser/guest_view/guest_view_manager.cc b/extensions/browser/guest_view/guest_view_manager.cc
index b7ddae913cb8c7fbf2a050471b3d5b70b9b56817..8ea6d96e4b1ff3b8664560e833743f86c7832c41 100644
--- a/extensions/browser/guest_view/guest_view_manager.cc
+++ b/extensions/browser/guest_view/guest_view_manager.cc
@@ -186,6 +186,14 @@ bool GuestViewManager::ForEachGuest(WebContents* owner_web_contents,
   return false;
 }
 
+WebContents* GuestViewManager::GetFullPageGuest(
+    WebContents* embedder_web_contents) {
+  WebContents* result = nullptr;
+  ForEachGuest(embedder_web_contents,
+               base::Bind(&GuestViewManager::GetFullPageGuestHelper, &result));
+  return result;
+}
+
 void GuestViewManager::AddGuest(int guest_instance_id,
                                 WebContents* guest_web_contents) {
   CHECK(!ContainsKey(guest_web_contents_by_instance_id_, guest_instance_id));
@@ -258,6 +266,18 @@ bool GuestViewManager::CanUseGuestInstanceID(int guest_instance_id) {
   return !ContainsKey(removed_instance_ids_, guest_instance_id);
 }
 
+// static
+bool GuestViewManager::GetFullPageGuestHelper(
+    content::WebContents** result,
+    content::WebContents* guest_web_contents) {
+  auto guest_view = GuestViewBase::FromWebContents(guest_web_contents);
+  if (guest_view && guest_view->is_full_page_plugin()) {
+    *result = guest_web_contents;
+    return true;
+  }
+  return false;
+}
+
 bool GuestViewManager::CanEmbedderAccessInstanceID(
     int embedder_render_process_id,
     int guest_instance_id) {