Create initial browser id for compositor on startup.

components/compositing/compositor.rs

@@ -23,7 +23,9 @@ use image::{DynamicImage, ImageFormat};
 use ipc_channel::ipc;
 use libc::c_void;
 use log::warn;
-use msg::constellation_msg::{PipelineId, PipelineIndex, PipelineNamespaceId};
+use msg::constellation_msg::{
+    PipelineId, PipelineIndex, PipelineNamespaceId, TopLevelBrowsingContextId,
+};
 use net_traits::image::base::Image;
 use net_traits::image_cache::CorsStatus;
 use num_traits::FromPrimitive;
@@ -104,6 +106,11 @@ impl FrameTreeId {
 #[derive(Clone, Copy, Debug)]
 enum LayerPixel {}
 
+struct RootPipeline {
+    top_level_browsing_context_id: TopLevelBrowsingContextId,
+    id: Option<PipelineId>,
+}
+
 /// NB: Never block on the constellation, because sometimes the constellation blocks on us.
 pub struct IOCompositor<Window: WindowMethods + ?Sized> {
     /// The application window.
@@ -113,7 +120,7 @@ pub struct IOCompositor<Window: WindowMethods + ?Sized> {
     port: CompositorReceiver,
 
     /// The root pipeline.
-    root_pipeline: Option<CompositionPipeline>,
+    root_pipeline: RootPipeline,
 
     /// Tracks details about each active pipeline that the compositor knows about.
     pipeline_details: HashMap<PipelineId, PipelineDetails>,
@@ -289,6 +296,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
         is_running_problem_test: bool,
         exit_after_load: bool,
         convert_mouse_to_touch: bool,
+        top_level_browsing_context_id: TopLevelBrowsingContextId,
     ) -> Self {
         let composite_target = match output_file {
             Some(_) => CompositeTarget::PngFile,
@@ -299,7 +307,10 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
             embedder_coordinates: window.get_coordinates(),
             window,
             port: state.receiver,
-            root_pipeline: None,
+            root_pipeline: RootPipeline {
+                top_level_browsing_context_id,
+                id: None,
+            },
             pipeline_details: HashMap::new(),
             scale: Scale::new(1.0),
             composition_request: CompositionRequest::NoCompositingNecessary,
@@ -342,6 +353,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
         is_running_problem_test: bool,
         exit_after_load: bool,
         convert_mouse_to_touch: bool,
+        top_level_browsing_context_id: TopLevelBrowsingContextId,
     ) -> Self {
         let mut compositor = IOCompositor::new(
             window,
@@ -350,6 +362,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
             is_running_problem_test,
             exit_after_load,
             convert_mouse_to_touch,
+            top_level_browsing_context_id,
         );
 
         // Make sure the GL state is OK
@@ -781,7 +794,10 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
             frame_tree.pipeline.id
         );
 
-        self.root_pipeline = Some(frame_tree.pipeline.clone());
+        self.root_pipeline = RootPipeline {
+            top_level_browsing_context_id: frame_tree.pipeline.top_level_browsing_context_id,
+            id: Some(frame_tree.pipeline.id),
+        };
 
         let pipeline_id = frame_tree.pipeline.id.to_webrender();
         let mut txn = webrender_api::Transaction::new();
@@ -823,10 +839,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
             initial_viewport: initial_viewport,
         };
 
-        let top_level_browsing_context_id = self
-            .root_pipeline
-            .as_ref()
-            .map(|pipeline| pipeline.top_level_browsing_context_id);
+        let top_level_browsing_context_id = self.root_pipeline.top_level_browsing_context_id;
 
         let msg = ConstellationMsg::WindowSize(top_level_browsing_context_id, data, size_type);
 
@@ -926,7 +939,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
     }
 
     fn dispatch_mouse_window_move_event_class(&mut self, cursor: DevicePoint) {
-        let root_pipeline_id = match self.get_root_pipeline_id() {
+        let root_pipeline_id = match self.root_pipeline.id {
             Some(root_pipeline_id) => root_pipeline_id,
             None => return,
         };
@@ -1204,10 +1217,7 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
     }
 
     fn constrain_viewport(&mut self, pipeline_id: PipelineId, constraints: ViewportConstraints) {
-        let is_root = self
-            .root_pipeline
-            .as_ref()
-            .map_or(false, |root_pipeline| root_pipeline.id == pipeline_id);
+        let is_root = self.root_pipeline.id == Some(pipeline_id);
 
         if is_root {
             self.viewport_zoom = constraints.initial_zoom;
@@ -1640,10 +1650,6 @@ impl<Window: WindowMethods + ?Sized> IOCompositor<Window> {
         );
     }
 
-    fn get_root_pipeline_id(&self) -> Option<PipelineId> {
-        self.root_pipeline.as_ref().map(|pipeline| pipeline.id)
-    }
-
     pub fn receive_messages(&mut self) -> bool {
         // Check for new messages coming from the other threads in the system.
         let mut compositor_messages = vec![];