Code: void RegisterOptimizationHintsComponent(ComponentUpdateService* cus,
                                        PrefService* profile_prefs) {
  if (!previews::params::IsOptimizationHintsEnabled()) {
     return;
   }
 
  bool data_saver_enabled =
      base::CommandLine::ForCurrentProcess()->HasSwitch(
          data_reduction_proxy::switches::kEnableDataReductionProxy) ||
      (profile_prefs && profile_prefs->GetBoolean(
                            data_reduction_proxy::prefs::kDataSaverEnabled));
  if (!data_saver_enabled)
     return;
   auto installer = base::MakeRefCounted<ComponentInstaller>(
       std::make_unique<OptimizationHintsComponentInstallerPolicy>());
   installer->Register(cus, base::OnceClosure());
}

Vulnerability Type: Overflow 
CWE ID: CWE-119
Summary: An off by one error resulting in an allocation of zero size in FFmpeg in Google Chrome prior to 54.0.2840.98 for Mac, and 54.0.2840.99 for Windows, and 54.0.2840.100 for Linux, and 55.0.2883.84 for Android allowed a remote attacker to potentially exploit heap corruption via a crafted video file.
Commit Message: Move IsDataSaverEnabledByUser to be a static method and use it

This method now officially becomes the source of truth that
everything in the code base eventually calls into to determine whether
or not DataSaver is enabled.

Bug: 934399
Change-Id: Iae837b710ace8cc3101188f79d02cbc2d4f0fd93
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1537242
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#643948}