Fix embedded PDFs when plugins are disabled

Cover all cases from https://pdfobject.com/static

- Plugin placeholder is generally broken: displays garbage and crashes
on interaction.  Fix it and show when PDFs are included by <embed>
or <object> tags.

- Do not start an automatical download when the disabled PDF plugin
was requested by an iframe. Show a clickable placeholder and let the
end-users start it manually.

- Remove unused class PluginPlaceholderQt

Task-number: QTBUG-76314
Change-Id: I01a0c93ab23f54e4272f5aeb30578de0dcf18932
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/core/content_browser_client_qt.cpp b/src/core/content_browser_client_qt.cpp
index c2c78ff8b..da1ea8dde 100644
--- a/src/core/content_browser_client_qt.cpp
+++ b/src/core/content_browser_client_qt.cpp
@@ -167,6 +167,7 @@
 #include "extensions/common/manifest_handlers/mime_types_handler.h"
 #include "extensions/extension_web_contents_observer_qt.h"
 #include "extensions/extensions_browser_client_qt.h"
+#include "extensions/pdf_iframe_navigation_throttle_qt.h"
 #include "net/plugin_response_interceptor_url_loader_throttle.h"
 #endif
 
@@ -222,6 +223,13 @@ bool IsHandledProtocol(base::StringPiece scheme)
 
 namespace QtWebEngineCore {
 
+void MaybeAddThrottle(
+    std::unique_ptr<content::NavigationThrottle> maybe_throttle,
+    std::vector<std::unique_ptr<content::NavigationThrottle>>* throttles) {
+    if (maybe_throttle)
+        throttles->push_back(std::move(maybe_throttle));
+}
+
 class QtShareGLContext : public gl::GLContext {
 public:
     QtShareGLContext(QOpenGLContext *qtContext)
@@ -1012,6 +1020,11 @@ std::vector<std::unique_ptr<content::NavigationThrottle>> ContentBrowserClientQt
                             navigation_handle,
                             base::BindRepeating(&navigationThrottleCallback),
                             navigation_interception::SynchronyMode::kSync));
+
+#if BUILDFLAG(ENABLE_EXTENSIONS)
+    MaybeAddThrottle(extensions::PDFIFrameNavigationThrottleQt::MaybeCreateThrottleFor(navigation_handle), &throttles);
+#endif
+
     return throttles;
 }