The mojo channel used for frame communication may disconnect for a variety of
reasons including frame navigation, frame destruction, or insertion into the
BackForwardCache (when the browser-side frame representation is destroyed and
closes the connection). When disconnect occurs we now evaluate the situation
and reconnect if appropriate.
Connections are now initiated solely from the renderer process and the
RenderFrame is passed as an argument to FrameAttached() instead of being
retrieved independently. Messages are queued while the frame is disconnected
and sent only after FrameAttachedAck() is received from the browser process.
The renderer process will be crashed intentionally with a "connection retry
failure" message if the reconnect fails 3 times in a row.
This change introduces a few minor CEF API behavior changes:
- A CefProcessMessage object cannot be reused after being passed to
SendProcessMessage.
- The |extra_info| argument to CefRenderProcessHandler::OnBrowserCreated may
now be NULL.
Where appropriate, we now utilize the default UTF string encoding format and
shared memory to reduce copies and conversions for the cross-process
transfer of arbitrary-length strings. For example, CefFrame::GetSource/GetText
now involves zero UTF conversions and zero copies in the browser process for
the CefString delivered to CefStringVisitor::Visit().
- Windows: 10.0.19041 SDK is now required.
- macOS: 10.15.1 SDK (at least Xcode 11.2) is now required.
- Remove CefMediaSource::IsValid and CefMediaSink::IsValid which would
always return true.
The PDF loading documentation in extension_system.cc has be updated to
describe the new code paths.
To support delivery of input events to the mime handler renderer process it is
now necessary to route events via the correct RWHV interface. For Aura-based
platforms (Windows/Linux) this means RWHVAura::On*Event and for macOS this
means RWHVMac::RouteOrProcess*Event. Since Aura uses UI event types these have
become the source of truth on Aura-based platforms with conversion to Web event
types when needed (primarily for OSR).
This change also adds a timeout for CefProcessHostMsg_GetNewBrowserInfo to
avoid a hung renderer process if the guest WebContents route is not
registered via CefMimeHandlerViewGuestDelegate::OnGuestDetached as expected
prior to CefBrowserInfoManager::OnGetNewBrowserInfo being called. This
timeout can be disabled for testing purposes by passing the
`--disable-new-browser-info-timeout` command-line flag.
The `--disable-features=MimeHandlerViewInCrossProcessFrame` command-line
flag can be used for a limited time to restore the previous implementation
based on BrowserPlugin. That implementation will be deleted starting with
the 3897 branch update.
Known issues:
- ExecuteJavaScript calls on the frame hosting the PDF extension will not
be routed to the mime handler renderer process.
- The PDF extension will not load successfully if blocked by
ChromePluginPlaceholder and then manually continued via the "Run this
plugin" context menu option (see https://crbug.com/533069#c41).
- The |category| value for all TRACE calls from CEF client applications is now
"cef.client" due to https://crrev.com/331266377d.
- The |with_menu_marker| parameter to CreateMenuButton has been removed due to
https://crrev.com/7f7e382118.
