Fixed case with no GLImage.

Regression occured in https://codereview.chromium.org/2006923006.
Because of incorrect merge with
https://codereview.chromium.org/2113443003.

BUG=625521
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2117103002
Cr-Commit-Position: refs/heads/master@{#403748}

gpu/ipc/service/image_transport_surface_overlay_mac.mm

@@ -332,11 +332,13 @@ void IOSurfaceContextNoOp(scoped_refptr<ui::IOSurfaceContext>) {
 
 bool ImageTransportSurfaceOverlayMac::ScheduleCALayer(
     const ui::CARendererLayerParams& params) {
-  gl::GLImageIOSurface* io_surface_image =
-      gl::GLImageIOSurface::FromGLImage(params.image);
-  if (!io_surface_image) {
-    DLOG(ERROR) << "Cannot schedule CALayer with non-IOSurface GLImage";
-    return false;
+  if (params.image) {
+    gl::GLImageIOSurface* io_surface_image =
+        gl::GLImageIOSurface::FromGLImage(params.image);
+    if (!io_surface_image) {
+      DLOG(ERROR) << "Cannot schedule CALayer with non-IOSurface GLImage";
+      return false;
+    }
   }
   return ca_layer_tree_coordinator_->GetPendingCARendererLayerTree()
       ->ScheduleCALayer(params);

ui/accelerated_widget_mac/ca_renderer_layer_tree.mm

@@ -394,13 +394,15 @@ bool AVSampleBufferDisplayLayerEnqueueIOSurface(
 
 void CARendererLayerTree::TransformLayer::AddContentLayer(
     const CARendererLayerParams& params) {
-  gl::GLImageIOSurface* io_surface_image =
-      gl::GLImageIOSurface::FromGLImage(params.image);
-  DCHECK(io_surface_image);
-  base::ScopedCFTypeRef<IOSurfaceRef> io_surface =
-      io_surface_image->io_surface();
-  base::ScopedCFTypeRef<CVPixelBufferRef> cv_pixel_buffer =
-      io_surface_image->cv_pixel_buffer();
+  base::ScopedCFTypeRef<IOSurfaceRef> io_surface;
+  base::ScopedCFTypeRef<CVPixelBufferRef> cv_pixel_buffer;
+  if (params.image) {
+    gl::GLImageIOSurface* io_surface_image =
+        gl::GLImageIOSurface::FromGLImage(params.image);
+    DCHECK(io_surface_image);
+    io_surface = io_surface_image->io_surface();
+    cv_pixel_buffer = io_surface_image->cv_pixel_buffer();
+  }
 
   content_layers.push_back(
       ContentLayer(io_surface, cv_pixel_buffer, params.contents_rect,