Proposal: Adding MemoryInfo to WebTiming

Hello,

Recently I added memory statistics info into WebKit, and it is already
available both in Chrome and in recent WebKit through
'webkitPerformance' interface. I was addressing the needs of GMail and
Wave developers who wanted to be able to track memory consumption
regressions. This feature was also warmly accepted by web developers,
and there is an implementation of a framework for visualizing timings
and memory data: http://github.com/mrdoob/stats.js

As the feature is already available, I decided that it's time to
update the WebTiming API spec. Here is my proposal:
http://bit.ly/bs2S8C

Please comment on whether this addition fits well into your scope. To
me, memory usage is just one aspect of performance. Memory overuse
leads to increased overhead for managing it, which leads to
performance degradation (e.g., specifically to JavaScript, excessive
memory usage leads to frequent garbage collections interrupting
virtual machine control flow and resulting in UI stalls.)

You can try the feature yourself using Chrome (stable version 6 is
OK), or Safari (need to download the latest WebKit version from
http://nightly.webkit.org/). As this feature has potential security
implications, it's only enabled when browser has certain run-time
flags set, please see "Enable MEM" section on
http://github.com/mrdoob/stats.js. After you have launched the browser
with flag set, open the page attached (without the flag set, stats
will always be 0.)