Move variations prefs into the variations component

These prefs are used by variations code that is targeted for componentization.

BUG=382865
TBR=thakis

Review URL: https://codereview.chromium.org/1265423003

Cr-Commit-Position: refs/heads/master@{#343661}
void HandleTestParameters(const base::CommandLine& command_line) {
  if (command_line.HasSwitch(switches::kBrowserCrashTest)) {
    int* bad_pointer = NULL;
    *bad_pointer = 0;
  }
}

void HandleTestParameters(const base::CommandLine& command_line) {
  if (command_line.HasSwitch(switches::kBrowserCrashTest)) {
    int* bad_pointer = NULL;
    *bad_pointer = 0;
  }
}
