Metrics for measuring how much overhead reading compressed content states adds.

BUG=104293
TEST=NONE

Review URL: https://chromiumcodereview.appspot.com/9426039

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@123733 0039d316-1c4b-4281-b951-d872f2087c98
void SessionService::TabNavigationPathPrunedFromBack(const SessionID& window_id,
                                                     const SessionID& tab_id,
                                                     int count) {
  if (!ShouldTrackChangesToWindow(window_id))
    return;

  TabNavigationPathPrunedFromBackPayload payload = { 0 };
  payload.id = tab_id.id();
  payload.index = count;
  SessionCommand* command =
      new SessionCommand(kCommandTabNavigationPathPrunedFromBack,
                         sizeof(payload));
  memcpy(command->contents(), &payload, sizeof(payload));
  ScheduleCommand(command);
}

void SessionService::TabNavigationPathPrunedFromBack(const SessionID& window_id,
                                                     const SessionID& tab_id,
                                                     int count) {
  if (!ShouldTrackChangesToWindow(window_id))
    return;

  TabNavigationPathPrunedFromBackPayload payload = { 0 };
  payload.id = tab_id.id();
  payload.index = count;
  SessionCommand* command =
      new SessionCommand(kCommandTabNavigationPathPrunedFromBack,
                         sizeof(payload));
  memcpy(command->contents(), &payload, sizeof(payload));
  ScheduleCommand(command);
}
