arc: Provide more logging for network failures.

components/arc/common/auth.mojom

Index: components/arc/common/auth.mojom
diff --git a/components/arc/common/auth.mojom b/components/arc/common/auth.mojom
index 0df2fa9c0480c40e6a6e82cf749c4a69568c2ea1..722581d3afbb58e819765d9489a7b1d3c18a5cba 100644
--- a/components/arc/common/auth.mojom
+++ b/components/arc/common/auth.mojom
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Next MinVersion: 8
+// Next MinVersion: 9
 
 module arc.mojom;
 
@@ -12,7 +12,7 @@ enum ArcSignInFailureReason {
   // Negative values are reserved for internal use.
   // The values are shuffled to keep the backward compatibility and don't match
   // ProvisioningResult in arc_optin_uma.h
-  // Next value: 15.
+  // Next value: 16.
   UNKNOWN_ERROR = 0,
 
   // Mojo errors:
@@ -61,6 +61,9 @@ enum ArcSignInFailureReason {
   CLOUD_PROVISION_FLOW_FAILED = 5,
   CLOUD_PROVISION_FLOW_TIMEOUT = 13,
   CLOUD_PROVISION_FLOW_INTERNAL_ERROR = 14,
+
+  // Network connection is unavailable.
+  [MinVersion=8] NO_NETWORK_CONNECTION = 15,

[khmel, 2017/03/01 20:39:09]

 [MinVersion=8] in enum is not sufficient to uprev host version. Dummy is added
to force this.

[Yusuke Sato, 2017/03/01 20:57:10]

What happens if you send NO_NETWORK_CONNECTION to older (version=7) Chrome?

If either Chrome or the container crashes (or wildly misbehaves), adding Dummy()
seems fine, but if nothing fatal (other than NOTREACHED logs, for example)
happens, just adding the enum but not adding Dummy() might be okay.

[Luis Héctor Chávez, 2017/03/01 21:00:06]

I'm also slightly against adding the dummy function. Please file a bug in crbug/
to make the code generator take this into account (add yzshen@, but he might not
be able to take this work immediately. w.c.s. I'll get to it by end of next
week).

[khmel, 2017/03/01 21:33:06]

Personally I also consider this as minor part but for 100% correctness needed to
do that trick.
Nothing dangerous happens in worse case when Android has updated version but
Chrome not. As I tested without dummy and tricky manipulation with mojo version
"Unknown error" is shown. So I removed dummy part. Also I will be landing Chrome
first and we should never face this case.

 };
 
 // These values describe the type of the Chrome account to provision.
@@ -115,7 +118,7 @@ struct AccountInfo {
   bool is_managed@2;
 };
 
-// Next Method ID: 9.
+// Next Method ID: 10.
 interface AuthHost {
   // Notifies Chrome that the sign-in is completed successfully.
   [MinVersion=2] OnSignInComplete@2();
@@ -129,6 +132,10 @@ interface AuthHost {
   // Reports metrics to Chrome to be recorded in UMA.
   [MinVersion=7] ReportMetrics@8(MetricsType metrics_type, int32 value);
 
+  // Dummy method to force update mojom version. [MinVersion=8] in enum
+  // ArcSignInFailureReasonhas has no effect.
+  [MinVersion=8] Dummy@9();

[Yusuke Sato, 2017/03/01 20:57:10]

Please move this to line 123 to lexicographically sort methods (that's the whole
point for having @N :)

[khmel, 2017/03/01 21:33:06]

Good point, however deprecated :)

+
   // Deprecated methods:
 
   // Returns an authorization code, which can be used to sign in.