constellation: Stop assuming that the viewport is shared by all WebViews (#36312)

The `Constellation` previously held a `window_size` member, but this
assumes that all `WebView`s have the same size. This change removes that
assumption as well as making sure that all `WebView`s pass their size
and HiDIP scaling to the `Constellation` when they are created.

In addition

- `WindowSizeData` is renamed to `ViewportDetails`, as it was
holding more than just the size and it didn't necessarily correspond to
  a "window." It's used for tracking viewport data, whether for an
  `<iframe>` or the main `WebView` viewport.
- `ViewportDetails` is stored more consistently so that conceptually an
  `<iframe>` can also have its own HiDPI scaling. This isn't something
  we necessarily want, but it makes everything conceptually simpler.

The goal with this change is to work toward allowing per-`WebView` HiDPI
scaling and sizing. There are still some corresponding changes in the
compositor to make that happen, but they will in a subsequent change.

Testing: This is covered by existing tests. There should be no behavior
changes.
Fixes: This is part of #36232.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/components/shared/script/script_msg.rs b/components/shared/script/script_msg.rs
index 8baf158312c..9d03ce2509c 100644
--- a/components/shared/script/script_msg.rs
+++ b/components/shared/script/script_msg.rs
@@ -13,8 +13,9 @@ use base::id::{
 use canvas_traits::canvas::{CanvasId, CanvasMsg};
 use constellation_traits::{LogEntry, TraversalDirection};
 use devtools_traits::{ScriptToDevtoolsControlMsg, WorkerId};
-use embedder_traits::{EmbedderMsg, MediaSessionEvent, TouchEventType, TouchSequenceId};
-use euclid::Size2D;
+use embedder_traits::{
+    EmbedderMsg, MediaSessionEvent, TouchEventType, TouchSequenceId, ViewportDetails,
+};
 use euclid::default::Size2D as UntypedSize2D;
 use ipc_channel::ipc::{IpcReceiver, IpcSender};
 use net_traits::CoreResourceMsg;
@@ -22,7 +23,6 @@ use net_traits::storage_thread::StorageType;
 use serde::{Deserialize, Serialize};
 use servo_url::{ImmutableOrigin, ServoUrl};
 use strum_macros::IntoStaticStr;
-use style_traits::CSSPixel;
 #[cfg(feature = "webgpu")]
 use webgpu_traits::{WebGPU, WebGPUAdapterResponse};
 use webrender_api::ImageKey;
@@ -39,8 +39,8 @@ use crate::{
 pub struct IFrameSizeMsg {
     /// The child browsing context for this iframe.
     pub browsing_context_id: BrowsingContextId,
-    /// The size of the iframe.
-    pub size: Size2D<f32, CSSPixel>,
+    /// The size and scale factor of the iframe.
+    pub size: ViewportDetails,
     /// The kind of sizing operation.
     pub type_: WindowSizeType,
 }