Split the Alloy runtime into bootstrap and style components. Support
creation of Alloy style browsers and windows with the Chrome runtime.
Chrome runtime (`--enable-chrome-runtime`) + Alloy style
(`--use-alloy-style`) supports Views (`--use-views`), native parent
(`--use-native`) and windowless rendering
(`--off-screen-rendering-enabled`).
Print preview is supported in all cases except with windowless rendering
on all platforms and native parent on MacOS. It is disabled by default
with Alloy style for legacy compatibility. Where supported it can be
enabled or disabled globally using `--[enable|disable]-print-preview` or
configured on a per-RequestContext basis using the
`printing.print_preview_disabled` preference. It also behaves as
expected when triggered via the PDF viewer print button.
Chrome runtime + Alloy style behavior differs from Alloy runtime in the
following significant ways:
- Supports Chrome error pages by default.
- DevTools popups are Chrome style only (cannot be windowless).
- The Alloy extension API will not supported.
Chrome runtime + Alloy style passes all expected Alloy ceftests except
the following:
- `DisplayTest.AutoResize` (Alloy extension API not supported)
- `DownloadTest.*` (Download API not yet supported)
- `ExtensionTest.*` (Alloy extension API not supported)
This change also adds Chrome runtime support for
CefContextMenuHandler::RunContextMenu (see #3293).
This change also explicitly blocks (and doesn't retry) FrameAttached
requests from PDF viewer and print preview excluded frames (see #3664).
Known issues specific to Chrome runtime + Alloy style:
- DevTools popup with windowless rendering doesn't load successfully.
Use windowed rendering or remote debugging as a workaround.
- Chrome style Window with Alloy style BrowserView (`--use-alloy-style
--use-chrome-style-window`) does not show Chrome theme changes.
To test:
- Run `ceftests --enable-chrome-runtime --use-alloy-style
[--use-chrome-style-window] [--use-views|--use-native]
--gtest_filter=...`
- Run `cefclient --enable-chrome-runtime --use-alloy-style
[--use-chrome-style-window]
[--use-views|--use-native|--off-screen-rendering-enabled]`
- Run `cefsimple --enable-chrome-runtime --use-alloy-style [--use-views]`
This functionality stopped being relevant after the removal of Flash support
in January 2021. The last remaining PPAPI plugin (PDF viewer) will switch to
a non-plugin implementation (PdfUnseasoned) in M100.
With PdfUnseasoned the PDF file will be loaded in a dedicated renderer process.
We identify this process by adding the kPdfRenderer command-line flag (similar
to how kExtensionProcess is used to identify an extension renderer process). We
then avoid calling GetNewBrowserInfo for the PDF renderer process because we
know the request will otherwise time out.
We need to override ChromeMimeHandlerViewGuestDelegate to handle
OnGuestAttached/Detached callbacks in order to account for the guest renderer
process hosting the PDF extension.
Additional work will be required to account for the renderer process hosting the
PDF viewer when using `--enable-features=PdfUnseasoned` (see issue #2969).
- Remove CefRequestContextHandler::OnBeforePluginLoad and
CefRequestContext::PurgePluginListCache (fixes issue #3047). These methods
stopped being relevant after the removal of Flash support in January 2021.
The last remaining PPAPI plugin (PDF viewer) will switch to a non-plugin
implementation in the near future (see https://crbug.com/702993#c58) and
functionality related to plugin filtering has already been removed in
https://crrev.com/343ae351c9.
Marshall Greenblatt