Auto merge of #16876 - asajeffrey:constellation-rename-frames, r=cbrewster

Renamed constellation::Frame to constellation::BrowsingContext

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Now that script has `WindowProxy` rather than `BrowsingContext` objects, we can rename `Frame` in the constellation to `BrowsingContext`. In particular, this means that `FrameId`s are now `BrowsingContextid`s, which better captures their purpose (and they are used in a lot of places, not just the constellation).

---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes do not require tests because renaming

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components/layout/display_list_builder.rs

@@ -34,7 +34,7 @@ use inline::{FIRST_FRAGMENT_OF_ELEMENT, InlineFlow, LAST_FRAGMENT_OF_ELEMENT};
 use ipc_channel::ipc;
 use list_item::ListItemFlow;
 use model::{self, MaybeAuto, specified};
-use msg::constellation_msg::FrameId;
+use msg::constellation_msg::BrowsingContextId;
 use net_traits::image::base::PixelFormat;
 use net_traits::image_cache::UsePlaceholder;
 use range::Range;
@@ -175,7 +175,7 @@ pub struct DisplayListBuildState<'a> {
 
     /// Vector containing iframe sizes, used to inform the constellation about
     /// new iframe sizes
-    pub iframe_sizes: Vec<(FrameId, TypedSize2D<f32, CSSPixel>)>,
+    pub iframe_sizes: Vec<(BrowsingContextId, TypedSize2D<f32, CSSPixel>)>,
 
     /// A stack of clips used to cull display list entries that are outside the
     /// rendered region.
@@ -1823,7 +1823,7 @@ impl FragmentDisplayListBuilding for Fragment {
 
                     let size = Size2D::new(item.bounds().size.width.to_f32_px(),
                                            item.bounds().size.height.to_f32_px());
-                    state.iframe_sizes.push((fragment_info.frame_id, TypedSize2D::from_untyped(&size)));
+                    state.iframe_sizes.push((fragment_info.browsing_context_id, TypedSize2D::from_untyped(&size)));
 
                     state.add_display_item(item);
                 }

components/layout/fragment.rs

@@ -26,7 +26,7 @@ use ipc_channel::ipc::IpcSender;
 use layout_debug;
 use model::{self, IntrinsicISizes, IntrinsicISizesContribution, MaybeAuto, SizeConstraint};
 use model::{style_length, ToGfxMatrix};
-use msg::constellation_msg::{FrameId, PipelineId};
+use msg::constellation_msg::{BrowsingContextId, PipelineId};
 use net_traits::image::base::{Image, ImageMetadata};
 use net_traits::image_cache::{ImageOrMetadataAvailable, UsePlaceholder};
 use range::*;
@@ -472,7 +472,7 @@ impl ImageFragmentInfo {
 #[derive(Clone)]
 pub struct IframeFragmentInfo {
     /// The frame ID of this iframe.
-    pub frame_id: FrameId,
+    pub browsing_context_id: BrowsingContextId,
     /// The pipelineID of this iframe.
     pub pipeline_id: PipelineId,
 }
@@ -480,10 +480,10 @@ pub struct IframeFragmentInfo {
 impl IframeFragmentInfo {
     /// Creates the information specific to an iframe fragment.
     pub fn new<N: ThreadSafeLayoutNode>(node: &N) -> IframeFragmentInfo {
-        let frame_id = node.iframe_frame_id();
+        let browsing_context_id = node.iframe_browsing_context_id();
         let pipeline_id = node.iframe_pipeline_id();
         IframeFragmentInfo {
-            frame_id: frame_id,
+            browsing_context_id: browsing_context_id,
             pipeline_id: pipeline_id,
         }
     }