[hidamon]

Why would they check if Adblock is installed or not?

https://code.google.com/p/chromium/codesearch#chromium/src/c...

  bool ChromeContentRendererClient::IsAdblockInstalled() {
    return g_current_client->extension_dispatcher_->extensions()->Contains(
        "gighmmpiobklfepjocnamgkkbiglidom");
  }

  bool ChromeContentRendererClient::IsAdblockPlusInstalled() {
    return g_current_client->extension_dispatcher_->extensions()->Contains(
        "cfhdojbkjhnklbpkdaibdccddilifddb");
  }

[elq]

They were apparently trying to understand performance issues with adblock, so they can fix them...

  // TODO(mpcomplete): remove the extension-related histograms after we collect
  // enough data. http://crbug.com/100411
  
  const bool use_adblock_histogram =
      ChromeContentRendererClient::IsAdblockInstalled();

https://code.google.com/p/chromium/issues/detail?id=100411