Better support for Cellular roaming state in ONC

This CL does the following:
* Eliminates "ProviderRequiresRoaming" from ONC
* Adds a "required" state to "RoamingState" in ONC when ProviderRequiresRoaming is true
* Adds "ONC State" to chrome://network for testing networkingPrivate.getState()
* Adds support for shill_stub=roaming=[home|roaming|required] to facilitate testing on Linux

BUG=461163

Review URL: https://codereview.chromium.org/948943003

Cr-Commit-Position: refs/heads/master@{#318113}

3 files changed, 11 insertions, 15 deletions

diff --git a/components/onc/docs/onc_spec.html b/components/onc/docs/onc_spec.html
index 8bf7e6d..b364ab7 100644
--- a/components/onc/docs/onc_spec.html
+++ b/components/onc/docs/onc_spec.html
@@ -2287,21 +2287,17 @@
       The revision of the Preferred Roaming List that is loaded in the modem.
     </dd>
 
-    <dt class="field">ProviderRequiresRoaming</dt>
-    <dd>
-      <span class="field_meta">(optional, read-only)
-        <span class="type">boolean</span>
-      </span>
-      Indicates that the cellular provider (determined based on IMSI and SPN)
-      requires roaming.
-    </dd>
-
     <dt class="field">RoamingState</dt>
     <dd>
       <span class="field_meta">(optional, read-only)
         <span class="type">string</span>
       </span>
       The roaming status of the cellular modem on the current network.
+      <span class="rule"><span class="rule_id"></span>
+        Allowed values are <span class="value">Home</span>,
+        <span class="value">Roaming</span>, or if the provider has no home
+        network, <span class="value">Required</span>.
+      </span>
     </dd>
 
     <dt class="field">ServingOperator</dt>
diff --git a/components/onc/onc_constants.cc b/components/onc/onc_constants.cc
index 06c69db..0c14f23 100644
--- a/components/onc/onc_constants.cc
+++ b/components/onc/onc_constants.cc
@@ -114,10 +114,10 @@ const char kMIN[] = "MIN";
 const char kModelID[] = "ModelID";
 const char kNetworkTechnology[] = "NetworkTechnology";
 const char kPRLVersion[] = "PRLVersion";
-const char kProviderRequiresRoaming[] = "ProviderRequiresRoaming";
+const char kRoamingHome[] = "Home";
+const char kRoamingRequired[] = "Required";
+const char kRoamingRoaming[] = "Roaming";
 const char kRoamingState[] = "RoamingState";
-const char kHome[] = "Home";
-const char kRoaming[] = "Roaming";
 const char kServingOperator[] = "ServingOperator";
 const char kSignalStrength[] = "SignalStrength";
 const char kSIMLockStatus[] = "SIMLockStatus";
diff --git a/components/onc/onc_constants.h b/components/onc/onc_constants.h
index 7d8f07e..6329ff8 100644
--- a/components/onc/onc_constants.h
+++ b/components/onc/onc_constants.h
@@ -132,10 +132,10 @@ ONC_EXPORT extern const char kMIN[];
 ONC_EXPORT extern const char kModelID[];
 ONC_EXPORT extern const char kNetworkTechnology[];
 ONC_EXPORT extern const char kPRLVersion[];
-ONC_EXPORT extern const char kProviderRequiresRoaming[];
+ONC_EXPORT extern const char kRoamingHome[];
+ONC_EXPORT extern const char kRoamingRequired[];
+ONC_EXPORT extern const char kRoamingRoaming[];
 ONC_EXPORT extern const char kRoamingState[];
-ONC_EXPORT extern const char kHome[];
-ONC_EXPORT extern const char kRoaming[];
 ONC_EXPORT extern const char kServingOperator[];
 ONC_EXPORT extern const char kSignalStrength[];
 ONC_EXPORT extern const char kSIMLockStatus[];