Fix PDF rendering with OSR (issue #1689)

libcef/browser/osr/render_widget_host_view_osr.cc

@@ -23,6 +23,7 @@
 #include "components/display_compositor/gl_helper.h"
 #include "content/browser/bad_message.h"
 #include "content/browser/compositor/image_transport_factory.h"
+#include "content/browser/frame_host/render_widget_host_view_guest.h"
 #include "content/browser/renderer_host/dip_util.h"
 #include "content/browser/renderer_host/render_widget_host_delegate.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
@@ -472,6 +473,7 @@ CefRenderWidgetHostViewOSR::CefRenderWidgetHostViewOSR(
 #endif
       weak_ptr_factory_(this) {
   DCHECK(render_widget_host_);
+  DCHECK(!render_widget_host_->GetView());
   render_widget_host_->SetView(this);
 
   // CefBrowserHostImpl might not be created at this time for popups.
@@ -1154,13 +1156,7 @@ void CefRenderWidgetHostViewOSR::Invalidate(
     return;
   }
 
-  const gfx::Rect& bounds_in_pixels = gfx::Rect(GetPhysicalBackingSize());
+  InvalidateInternal(gfx::Rect(GetPhysicalBackingSize()));
-
-  if (software_output_device_) {
-    software_output_device_->OnPaint(bounds_in_pixels);
-  } else if (copy_frame_generator_.get()) {
-    copy_frame_generator_->GenerateCopyFrame(true, bounds_in_pixels);
-  }
 }
 
 void CefRenderWidgetHostViewOSR::SendKeyEvent(
@@ -1314,6 +1310,14 @@ void CefRenderWidgetHostViewOSR::RemoveGuestHostView(
   guest_host_views_.erase(guest_host);
 }
 
+void CefRenderWidgetHostViewOSR::RegisterGuestViewFrameSwappedCallback(
+    content::RenderWidgetHostViewGuest* guest_host_view) {
+  guest_host_view->RegisterFrameSwappedCallback(base::MakeUnique<base::Closure>(
+      base::Bind(&CefRenderWidgetHostViewOSR::OnGuestViewFrameSwapped,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 base::Unretained(guest_host_view))));
+}
+
 #if !defined(OS_MACOSX)
 
 ui::Compositor* CefRenderWidgetHostViewOSR::GetCompositor() const {
@@ -1495,3 +1499,20 @@ void CefRenderWidgetHostViewOSR::OnScrollOffsetChanged() {
   }
   is_scroll_offset_changed_pending_ = false;
 }
+
+void CefRenderWidgetHostViewOSR::OnGuestViewFrameSwapped(
+    content::RenderWidgetHostViewGuest* guest_host_view) {
+  InvalidateInternal(
+      gfx::ConvertRectToPixel(scale_factor_, guest_host_view->GetViewBounds()));
+
+  RegisterGuestViewFrameSwappedCallback(guest_host_view);
+}
+
+void CefRenderWidgetHostViewOSR::InvalidateInternal(
+    const gfx::Rect& bounds_in_pixels) {
+  if (software_output_device_) {
+    software_output_device_->OnPaint(bounds_in_pixels);
+  } else if (copy_frame_generator_.get()) {
+    copy_frame_generator_->GenerateCopyFrame(true, bounds_in_pixels);
+  }
+}

libcef/browser/osr/render_widget_host_view_osr.h

@@ -34,6 +34,7 @@
 namespace content {
 class RenderWidgetHost;
 class RenderWidgetHostImpl;
+class RenderWidgetHostViewGuest;
 class BackingStore;
 }
 
@@ -249,6 +250,11 @@ class CefRenderWidgetHostViewOSR
   void AddGuestHostView(CefRenderWidgetHostViewOSR* guest_host);
   void RemoveGuestHostView(CefRenderWidgetHostViewOSR* guest_host);
 
+  // Register a callback that will be executed when |guest_host_view| receives
+  // OnSwapCompositorFrame. The callback triggers repaint of the embedder view.
+  void RegisterGuestViewFrameSwappedCallback(
+      content::RenderWidgetHostViewGuest* guest_host_view);
+
   CefRefPtr<CefBrowserHostImpl> browser_impl() const { return browser_impl_; }
   void set_browser_impl(CefRefPtr<CefBrowserHostImpl> browser) {
     browser_impl_ = browser;
@@ -282,6 +288,11 @@ class CefRenderWidgetHostViewOSR
 
   void OnScrollOffsetChanged();
 
+  void OnGuestViewFrameSwapped(
+      content::RenderWidgetHostViewGuest* guest_host_view);
+
+  void InvalidateInternal(const gfx::Rect& bounds_in_pixels);
+
 #if defined(OS_MACOSX)
   friend class MacHelper;
 

libcef/browser/osr/web_contents_view_osr.cc

@@ -139,10 +139,13 @@ content::RenderWidgetHostViewBase* CefWebContentsViewOSR::CreateViewForWidget(
                                        embedder_host_view);
     embedder_host_view->AddGuestHostView(platform_widget);
 
-    return content::RenderWidgetHostViewGuest::Create(
+    content::RenderWidgetHostViewGuest* guest_host_view =
+        content::RenderWidgetHostViewGuest::Create(
             render_widget_host,
             guest_,
             platform_widget->GetWeakPtr());
+    embedder_host_view->RegisterGuestViewFrameSwappedCallback(guest_host_view);
+    return guest_host_view;
   }
 
   view_ = new CefRenderWidgetHostViewOSR(transparent_, render_widget_host,