Adjustable Auction

adjustable_auction.cc is a browsertest-based tool for running simulated auctions with custom command line parameters. The tool is useful for profiling hypothetical scenarios locally.

To use the tool:

1. Ensure your gn build configuration has is_debug = false so that you produce a release build.
2. Build with autoninja -C out/{target} adjustable_auction.
3. Choose which parameters to use when configuring the auction. Most parameters control aspects of the auctions (e.g. --n-auctions, --ads-per-ig). Others are important to allow us to collect accurate latency information. --hist-filename is the filename to save UMA histograms from the auction. Set a large enough --preauction-delay to ensure all interest groups have already been joined before starting an auction. See SetUpCommandLineArgs() in adjustable_auction.cc for a full list of parameters and their descriptions.
4. If your auction is likely to take a long time, you may want to increase the test timeouts with --ui-test-action-max-timeout=1000000 and
   --test-launcher-timeout=1000000.
5. This tool is particularly useful when used with the perf command line tool. A delay can be set with -D equal to the delay set with --preauction-delay to ensure that only the auctions are captured, not any of the set up. The following is an example of running perf with the tool:

perf record -e cpu-clock -F 8000 -D 10000 -o perf_output_file.data -g out/{target}/adjustable_auction ---ozone-platform=headless --ads-per-ig=30 --n-auctions=1 --owners=2 --ig-per-owner=100 --scoring-delay=0 --preauction-delay=10 --bidding-delay=10 --hist-filename=output_histograms.txt