Allows client to access auth token from command line specified file.

blimp/client/session/assignment_source_unittest.cc

Index: blimp/client/session/assignment_source_unittest.cc
diff --git a/blimp/client/session/assignment_source_unittest.cc b/blimp/client/session/assignment_source_unittest.cc
index 440b4dfe2ed8aa76eb8c24cbd2ff3aab567de5be..883e03ebc061e688811995ba7ca2e6d8864b2713 100644
--- a/blimp/client/session/assignment_source_unittest.cc
+++ b/blimp/client/session/assignment_source_unittest.cc
@@ -16,6 +16,8 @@
 #include "base/thread_task_runner_handle.h"
 #include "base/values.h"
 #include "blimp/client/app/blimp_client_switches.h"
+#include "blimp/common/fake_commandline.h"
+#include "blimp/common/get_client_token.h"
 #include "blimp/common/protocol_version.h"
 #include "components/safe_json/testing_json_parser.h"
 #include "net/base/test_data_directory.h"
@@ -82,6 +84,8 @@ class AssignmentSourceTest : public testing::Test {
     ASSERT_FALSE(cert_list.empty());
     cert_ = std::move(cert_list[0]);
     ASSERT_TRUE(cert_);
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());

[Kevin M, 2016/05/11 00:39:57]

See what we're doing with kCertRelativePath to get an idea of how we can use the
test_client_token file.

[CJ, 2016/05/11 23:48:49]

Done.

+    CreateFileForSwitch(engine::kClientTokenPath, kTestClientToken);
   }
 
   // This expects the AssignmentSource::GetAssignment to return a custom
@@ -196,10 +200,11 @@ AssignmentSourceTest::BuildAssignerResponse() {
 }
 
 TEST_F(AssignmentSourceTest, TestTCPAlternateEndpointSuccess) {
+  auto cmd_line = CreateCommandLine(all_filepath_switches_);
   Assignment assignment;
   assignment.transport_protocol = Assignment::TransportProtocol::TCP;
   assignment.engine_endpoint = net::IPEndPoint(kTestIpAddress, kTestPort);
-  assignment.client_token = kDummyClientToken;
+  assignment.client_token = GetClientToken(cmd_line);
   assignment.cert = scoped_refptr<net::X509Certificate>(nullptr);
 
   base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
@@ -217,10 +222,11 @@ TEST_F(AssignmentSourceTest, TestTCPAlternateEndpointSuccess) {
 }
 
 TEST_F(AssignmentSourceTest, TestSSLAlternateEndpointSuccess) {
+  auto cmd_line = CreateCommandLine(all_filepath_switches_);
   Assignment assignment;
   assignment.transport_protocol = Assignment::TransportProtocol::SSL;
   assignment.engine_endpoint = net::IPEndPoint(kTestIpAddress, kTestPort);
-  assignment.client_token = kDummyClientToken;
+  assignment.client_token = GetClientToken(cmd_line);
   assignment.cert = cert_;
 
   base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(