Chrome 152 stable ships a standard CPU performance tier API, a network allowlist header, and CSSPseudoElement targets for backdrop clicks and mid-flight view transitions.
Chrome 152 stable ships the CPU Performance API, which gives the page a tier rating for the device's CPU. If your app scales graphical fidelity, runs heavy canvas or WebGL work, or trims background tasks, read the tier and adapt instead of sniffing the user agent or benchmarking at startup. It layers on Compute Pressure for real-time load, and users can override the reported tier in Settings.
The CSS side expands CSSPseudoElement to ::backdrop, ::scroll-marker, and ::view-transition. You can script a click on a dialog's backdrop without the old intersection-math dance, hook scroll markers, and grab a view transition partway through using the coordinates of the elements still animating.
Connection Allowlists is the security item: a Connection-Allowlist response header gates every network request a document or worker initiates behind an explicit allowlist of endpoints. If you run a security-sensitive app, that is a real lever against unexpected outbound calls. Two smaller wins round it out: the alpha() function from Color 5 sets just a relative color's alpha channel, so you stop spelling out a full color to tweak opacity, and app-region becomes window-drag for draggable title-bar areas in installed desktop PWAs.
None of these break anything, so the Monday call is triage: performance-tier work gets a standard API, view-transition-heavy UI gets scripting hooks, and the header allowlist is worth a read if third-party network calls keep biting you.
Two long-awaited CSS features landed in Chrome 147: border-shape for non-rectangular element borders, and element-scoped view transitions that animate individual components without full-page transitions. Here's how they work and what they replace.
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Chrome 154 enforces CORS and Local Network Access for Background Fetch targets on localhost and the LAN, the one item here that needs work before the September 22 stable. The CSS additions are branch work, and text decoration insets retire gradient underline hacks.
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Firefox 156 now reports `::-webkit-scrollbar` as unsupported in `@supports`, flipping negated feature queries onto standard scrollbar properties, and moves `text-box-trim` onto `::first-line` metrics.
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