Teach the network service to clear its disk cache if requested.

mojo/services/network/network_service_delegate.cc

Index: mojo/services/network/network_service_delegate.cc
diff --git a/mojo/services/network/network_service_delegate.cc b/mojo/services/network/network_service_delegate.cc
index 76e0b6924b2eba979a933e699ebf103a8c042647..eb3b73be91f3041cdab8c2f80503da028e798682 100644
--- a/mojo/services/network/network_service_delegate.cc
+++ b/mojo/services/network/network_service_delegate.cc
@@ -6,8 +6,12 @@
 
 #include "base/at_exit.h"
 #include "base/base_paths.h"
+#include "base/command_line.h"
+#include "base/bind.h"
+#include "base/threading/thread.h"
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "third_party/mojo/src/mojo/public/cpp/application/application_connection.h"
 
@@ -20,6 +24,16 @@ void NetworkServiceDelegate::Initialize(mojo::ApplicationImpl* app) {
   base::FilePath base_path;
   CHECK(PathService::Get(base::DIR_TEMP, &base_path));
   base_path = base_path.Append(FILE_PATH_LITERAL("network_service"));
+  base::CommandLine command_line(app->args());
+  if (command_line.HasSwitch("clear")) {
+    scoped_ptr<base::Thread> cache_delete_thread(
+        new base::Thread("network cache delete thread"));
+    cache_delete_thread->Start();
+    mojo::NetworkContext::ClearCache(
+        base_path, cache_delete_thread->task_runner(),
+        base::Bind(&base::Thread::Stop,
+                   base::Owned(cache_delete_thread.release())));
+  }
   context_.reset(new mojo::NetworkContext(base_path));
 }