With the introduction of prerendering in Chromium it is now possible for
RenderFrameHosts (RFH) to move between FrameTrees. As a consequence we can no
longer rely on FrameTreeNode IDs to uniquely identify a RFH over its lifespan.
We must now switch to using GlobalRenderFrameHostId (child_id, frame_routing_id)
instead for that purpose. Additionally, we simplify existing code by using the
GlobalRenderFrameHostId struct in all places that previously used a
(render_process_id, render_frame_id) pair, since these concepts are equivalent.
See https://crbug.com/1179502#c8 for additional background.
See the new cef_frame_handler.h for complete usage documentation.
This change includes the following related enhancements:
- The newly added CefBrowser::IsValid method will return false (in the browser
process) after CefLifeSpanHandler::OnBeforeClose is called.
- CefBrowser::GetMainFrame will return a valid object (in the browser process)
until after CefLifeSpanHandler::OnBeforeClose is called.
- The main frame object will change during cross-origin navigation or
re-navigation after renderer process termination. During that time,
GetMainFrame will return the new/pending frame (in the browser process) and
any messages that arrive for the new/pending frame will be correctly
attributed in OnProcessMessageReceived.
- Commands to be executed in the renderer process that may fail during early
frame initialization (ExecuteJavaScript, LoadRequest, etc.) will now be
queued until after the JavaScript context for the frame has been created.
- Logging has been added for any commands that are dropped because they arrived
after frame detachment.
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().
With the Chrome runtime, Profile initialization may be asynchronous. Code that
waited on CefBrowserContext creation now needs to wait on CefBrowserContext
initialization instead.
The Chrome browser can now be hosted in a Views-based application on Windows
and Linux.
To launch a fully-featured Chrome window using cefsimple:
$ cefsimple --enable-chrome-runtime
To launch a minimally-styled Views-hosted window using cefsimple:
$ cefsimple --enable-chrome-runtime --use-views
To launch a fully-styled Views-hosted window using cefclient:
$ cefclient --enable-chrome-runtime --use-views
Views unit tests also now pass with the Chrome runtime enabled:
$ ceftests --gtest_filter=Views* --enable-chrome-runtime
Known issues:
- Popup browsers cannot be intercepted and reparented.
This change adds support for:
- Protocol and request handling.
- Loading and navigation events.
- Display and focus events.
- Mouse/keyboard events.
- Popup browsers.
- Callbacks in the renderer process.
- Misc. functionality required for ceftests.
This change also adds a new CefBrowserProcessHandler::GetCookieableSchemes
callback for configuring global state that will be applied to all
CefCookieManagers by default. This global callback is currently required by the
chrome runtime because the primary ProfileImpl is created via
ChromeBrowserMainParts::PreMainMessageLoopRun (CreatePrimaryProfile) before
OnContextCreated can be called.
ProfileImpl will use the "C:\Users\[user]\AppData\Local\CEF\User Data\Default"
directory by default (on Windows). Cookies may persist in this directory when
running ceftests and may need to be manually deleted if those tests fail.
Remaining work includes:
- Support for client-created request contexts.
- Embedding the browser in a Views hierarchy (cefclient support).
- TryCloseBrowser and DoClose support.
- Most of the CefSettings configuration.
- DevTools protocol and window control (ShowDevTools, ExecuteDevToolsMethod).
- CEF-specific WebUI pages (about, license, webui-hosts).
- Context menu customization (CefContextMenuHandler).
- Auto resize (SetAutoResizeEnabled).
- Zoom settings (SetZoomLevel).
- File dialog runner (RunFileDialog).
- File and JS dialog handlers (CefDialogHandler, CefJSDialogHandler).
- Extension loading (LoadExtension, etc).
- Plugin loading (OnBeforePluginLoad).
- Widevine loading (CefRegisterWidevineCdm).
- PDF and print preview does not display.
- Crash reporting is untested.
- Mac: Web content loads but does not display.
The following ceftests are now passing when run with the
"--enable-chrome-runtime" command-line flag:
CorsTest.*
DisplayTest.*:-DisplayTest.AutoResize
DOMTest.*
DraggableRegionsTest.*
ImageTest.*
MessageRouterTest.*
NavigationTest.*
ParserTest.*
RequestContextTest.*Global*
RequestTest.*
ResourceManagerTest.*
ResourceRequestHandlerTest.*
ResponseTest.*
SchemeHandlerTest.*
ServerTest.*
StreamResourceHandlerTest.*
StreamTest.*
StringTest.*
TaskTest.*
TestServerTest.*
ThreadTest.*
URLRequestTest.*Global*
V8Test.*:-V8Test.OnUncaughtExceptionDevTools
ValuesTest.*
WaitableEventTest.*
XmlReaderTest.*
ZipReaderTest.*
The Browser object represents the top-level Chrome browser window. One or more
tabs (WebContents) are then owned by the Browser object via TabStripModel. A
new Browser object can be created programmatically using "new Browser" or
Browser::Create, or as a result of user action such as dragging a tab out of an
existing window. New or existing tabs can also be added to an already existing
Browser object.
The Browser object acts as the WebContentsDelegate for all attached tabs. CEF
integration requires WebContentsDelegate callbacks and notification of tab
attach/detach. To support this integration we add a cef::BrowserDelegate
(ChromeBrowserDelegate) member that is created in the Browser constructor and
receives delegation for the Browser callbacks. ChromeBrowserDelegate creates a
new ChromeBrowserHostImpl when a tab is added to a Browser for the first time,
and that ChromeBrowserHostImpl continues to exist until the tab's WebContents
is destroyed. The associated WebContents object does not change, but the
Browser object will change when the tab is dragged between windows.
CEF callback logic is shared between the chrome and alloy runtimes where
possible. This shared logic has been extracted from CefBrowserHostImpl to
create new CefBrowserHostBase and CefBrowserContentsDelegate classes. The
CefBrowserHostImpl class is now only used with the alloy runtime and will be
renamed to AlloyBrowserHostImpl in a future commit.
Marshall Greenblatt
Dmitry Azaraev