Add config gerrit.primaryWeblinkName

Add gerrit.primaryWeblinkName to ServerInfo.
Lets the UI know which is the preferred weblink in instances were
only one weblink can be used, for example in inline links.

Change-Id: I01deaca3418d5c0486e3f5ebabf10827d47c3631

Documentation/config-gerrit.txt

@@ -2174,6 +2174,22 @@ Example:
   installModule = com.example.abc.OurSpecialSauceModule
 ----
 
+[[gerrit.primaryWeblinkName]]gerrit.primaryWeblinkName::
++
+Name of the link:dev-plugins.html#links-to-external-tools[Weblink] that should
+be chosen in cases where only one Weblink can be used in the UI, for example in
+inline links.
++
+By default unset, meaning that the UI is responsible for trying to identify
+a weblink to be used in these cases, most likely weblinks that links to code
+browsers with known integrations with Gerrit (like Gitiles and Gitweb).
++
+Example:
+----
+[gerrit]
+  primaryWeblinkName = gitiles
+----
+
 [[gerrit.reportBugUrl]]gerrit.reportBugUrl::
 +
 URL to direct users to when they need to report a bug.

java/com/google/gerrit/extensions/common/GerritInfo.java

@@ -26,4 +26,5 @@ public class GerritInfo {
   public String reportBugUrl;
   public String reportBugText;
   public Set<UiType> webUis;
+  public String primaryWeblinkName;
 }

java/com/google/gerrit/server/restapi/config/GetServerInfo.java

@@ -313,6 +313,7 @@ public class GetServerInfo implements RestReadView<ConfigResource> {
     if (gerritOptions.enableGwtUi()) {
       info.webUis.add(UiType.GWT);
     }
+    info.primaryWeblinkName = config.getString("gerrit", null, "primaryWeblinkName");
     return info;
   }