Relocate the WASM workspace from ui/webui/resources/wasm/ to
third_party/wasm/, following the convention of third_party/rust/.
This is a plain move with path updates — no structural changes to
the workspace, crate locations within it, or build targets.
This commit migrates the SplitView implementation from using individual
views for secondary content management to utilizing the centralized
BraveContentsContainerView. This change eliminates code duplication and
improves maintainability by leveraging existing infrastructure.
**Key Changes:**
** SplitView Architecture Refactoring:**
- Replace direct management of secondary_contents_web_view_,
secondary_devtools_web_view_, secondary_reader_mode_toolbar_,
secondary_lens_overlay_view_, and secondary_contents_scrim_view_
- Migrate to using a single BraveContentsContainerView instance that
encapsulates all secondary content management
** View Hierarchy Simplification:**
- secondary_contents_container_ (raw View) → secondary_contents_container_view_
(BraveContentsContainerView)
- All secondary view access now goes through the container view's accessors
- Unified layout management through BraveContentsContainerView
**Benefits:**
- Reduces code duplication between primary and secondary content management
- Leverages existing ContentsContainerView infrastructure for DevTools,
scrim views, lens overlay, and reader mode toolbar
- Simplifies view hierarchy and improves maintainability
- Better separation of concerns with centralized content management
Anthony Tseng