platform2: Explicitly use base:: namespace with CommandLine

The current revision of libchrome is removing CommandLine class
from global namespace and only retain the one in base::.

Sweep the code to use the correct namespace in anticpation of
libchrome revision roll.

BUG=None
TEST=./build_packages

Change-Id: Ib7ca448dac1204c1e36ab053e775a5a5214997ac
Reviewed-on: https://chromium-review.googlesource.com/263785
Trybot-Ready: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/crash_reporter/list_proxies.cc b/crash_reporter/list_proxies.cc
index de02f0a..de6ef0a 100644
--- a/crash_reporter/list_proxies.cc
+++ b/crash_reporter/list_proxies.cc
@@ -245,8 +245,8 @@
 }  // namespace
 
 int main(int argc, char *argv[]) {
-  CommandLine::Init(argc, argv);
-  CommandLine* cl = CommandLine::ForCurrentProcess();
+  base::CommandLine::Init(argc, argv);
+  base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
 
   if (cl->HasSwitch(kHelp)) {
     LOG(INFO) << kHelpMessage;
@@ -273,7 +273,7 @@
   chromeos::InitLog(init_flags);
 
   std::string url;
-  CommandLine::StringVector urls = cl->GetArgs();
+  base::CommandLine::StringVector urls = cl->GetArgs();
   if (!urls.empty()) {
     url = urls[0];
     LOG(INFO) << "Resolving proxies for URL: " << url;