[iOS CBCM] Don't send machine name in DM requests

Stops setting the machine_name field in the DM API protos for iOS
browsers. The machine name will instead be set by the backend by using
the client ID, and fall back to the device model if needed.

Bug: 1150847
Change-Id: I00345b07bce3b5f99fce3e19cd753207da4e6113
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2617465Reviewed-by: Fabio Tirelo <ftirelo@chromium.org>
Reviewed-by: Owen Min <zmin@chromium.org>
Commit-Queue: Guillaume Jenkins <gujen@google.com>
Cr-Commit-Position: refs/heads/master@{#843698}

components/policy/core/common/cloud/cloud_policy_client.cc

@@ -277,7 +277,11 @@ void CloudPolicyClient::RegisterWithToken(const std::string& token,
 
   enterprise_management::RegisterBrowserRequest* request =
       config->request()->mutable_register_browser_request();
+#if !defined(OS_IOS)
+  // For iOS devices, the machine name is determined by server side logic using
+  // the client ID and / or the device model.
   request->set_machine_name(GetMachineName());
+#endif  // !defined(OS_IOS)
   request->set_os_platform(GetOSPlatform());
   request->set_os_version(GetOSVersion());
 #if defined(OS_IOS)

components/policy/core/common/cloud/cloud_policy_client_unittest.cc

@@ -292,7 +292,9 @@ class CloudPolicyClientTest : public testing::Test {
     (defined(OS_LINUX) || BUILDFLAG(IS_CHROMEOS_LACROS))
     em::RegisterBrowserRequest* enrollment_request =
         enrollment_token_request_.mutable_register_browser_request();
+#if !defined(OS_IOS)
     enrollment_request->set_machine_name(policy::GetMachineName());
+#endif
     enrollment_request->set_os_platform(policy::GetOSPlatform());
     enrollment_request->set_os_version(policy::GetOSVersion());
 #if defined(OS_IOS)

components/policy/test_support/policy_testserver.py

@@ -900,8 +900,8 @@ class PolicyRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):
     if not device_id:
       return (400, 'Parameter deviceid is missing.')
 
-    if not msg.machine_name:
-      return (400, 'Invalid machine name: ')
+    if not msg.machine_name and not msg.device_model:
+      return (400, 'Either machine name or device model must be non-empty.')
 
     if enrollment_token == INVALID_ENROLLMENT_TOKEN:
       return (401, 'Invalid enrollment token')