We attach it to WorkerPrivate and DOMNavigationTiming so it will be re-used
when it should.
WorkerPrivate is used in the Performance APIs, Performance Storage Worker,
and Event.
DOMNavigationTiming is used only in the Performance APIs, but the crucial
part is that when the individual DOMNavigationTiming object is re-used,
so will the context seed. This in particular came up with the
nav2_test_document_open.html Web Platform Test which illustrated the fact
that even if you .open() a new document, the performance navigation data
is not supposed to change.
MozReview-Commit-ID: GIv6biEo2jY
PresShell only uses performane.now to track refresh times, and notify internal
observers. We can provide more accurate times by not clamping and jittering
these numbers.
MozReview-Commit-ID: FkDGJhrLeAy
Currently the Gecko Profiler defines a moderate amount of stuff when
MOZ_GECKO_PROFILER is undefined. It also #includes various headers, including
JS ones. This is making it difficult to separate Gecko's media stack for
inclusion in Servo.
This patch greatly simplifies how things are exposed. The starting point is:
- GeckoProfiler.h can be #included unconditionally;
- everything else from the profiler must be guarded by MOZ_GECKO_PROFILER.
In practice this introduces way too many #ifdefs, so the patch loosens it by
adding no-op macros for a number of the most common operations.
The net result is that #ifdefs and macros are used a bit more, but almost
nothing is exposed in non-MOZ_GECKO_PROFILER builds (including
ProfilerMarkerPayload.h and GeckoProfiler.h), and understanding what is exposed
is much simpler than before.
Note also that in BHR, ThreadStackHelper is now entirely absent in
non-MOZ_GECKO_PROFILER builds.
As well as the obvious #ifdef stuff, the patch removes
TCPSocket::SetAppIdAndBrowser(), which means
{TCPSocketParent,TCPServerSocketParent}::{GetAppId,GetInIsolatedMozBrowser}()
can also be removed.
This requires:
- Moving the constructors of ProfilerMarkerPayload and its subclasses into the
.h file so they are visible even when ProfilerMarkerPayload.cpp isn't
compiled.
- Similarly, using a macro to make StreamPayload() a crashing no-op when the
profiler isn't enabled. (It is never called in that case.)
Once the |aPayload| argument to profile_add_marker() became a UniquePtr the
default value of nullptr caused compilation difficulties that could only be
fixed by #including ProfilerMarkerPayload.h into lots of additional places
(because the UniquePtr<T> instantiation required the T to be fully defined). To
get around this I just split profile_add_marker() into two functions, one with
1 argument and one with 2 arguments.
The patch also removes the definition of PROFILER_MARKER_PAYLOAD in the case
where MOZ_GECKO_PROFILER isn't defined. A comment explains why.
This patch is going to neutralize the threat of fingerprinting of performance API
by spoofing the value of performance timing into 0, making getEntries* functions
always returns an empty list and making mark() and measure() into NOP methods.
In addition, this patch changes nsContentUtils::ShouldResistFingerprinting() to
allow it can be called in both main thread and worker threads.
MozReview-Commit-ID: C8Jt7KEMe5e
This patch is adapted from Tor bug 1517.
To offer some protection against timing attacks by JS content pages, in this
patch we round the various time-exposing APIs (such as Date and
Event.timeStamps) to the nearest 100 ms when the pref "privacy.resistFingerprinting" is on.
MozReview-Commit-ID: eGucM9nGTn
Because ProfilerMarkerPayload is the main type defined in these files, and
because the next patch is going to introduce ProfilerMarker.{h,cpp}, which
would be confusingly similar to the old names.
