Add support for plugin-owned capabilities

Plugin contributed SSH commands and UiActions can now be annotated
with plugin-owned capabilities.

Capability scope was introduced to differentiate between plugin-owned
capabilities and core capabilities. Per default the scope of
@RequiresCapability annotation is CapabilityScope.CONTEXT, i. e. when
@RequiresCapability is used within a plugin the scope of the capability is
assumed to be that plugin. If @RequiresCapability is used within the core
Gerrit Code Review server (and thus is outside of a plugin) the scope is the
core server and will use the GlobalCapability known to Gerrit Code Review
server.

If a plugin needs to use a core capability name (e.g. "administrateServer")
this can be specified by setting scope = CapabilityScope.CORE:

  @RequiresCapability(value="administrateServer", scope=CapabilityScope.CORE)

Change-Id: I82f7a6fef2a47613a1fd9c7474ff568db3ca84a2

gerrit-server/src/test/java/com/google/gerrit/server/config/ListCapabilitiesTest.java

@@ -19,21 +19,55 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
 import com.google.gerrit.common.data.GlobalCapability;
+import com.google.gerrit.extensions.annotations.Exports;
+import com.google.gerrit.extensions.config.CapabilityDefinition;
+import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.server.config.ListCapabilities.CapabilityInfo;
+import com.google.inject.AbstractModule;
+import com.google.inject.Guice;
+import com.google.inject.Injector;
 
+import org.junit.Before;
 import org.junit.Test;
 
 import java.util.Map;
 
 public class ListCapabilitiesTest {
+  private Injector injector;
+
+  @Before
+  public void setUp() throws Exception {
+    AbstractModule mod = new AbstractModule() {
+      @Override
+      protected void configure() {
+        DynamicMap.mapOf(binder(), CapabilityDefinition.class);
+        bind(CapabilityDefinition.class)
+          .annotatedWith(Exports.named("printHello"))
+          .toInstance(new CapabilityDefinition() {
+            @Override
+            public String getDescription() {
+              return "Print Hello";
+            }
+          });
+      }
+    };
+    injector = Guice.createInjector(mod);
+  }
+
   @Test
   public void testList() throws Exception {
     Map<String, CapabilityInfo> m =
-        new ListCapabilities().apply(new ConfigResource());
+        injector.getInstance(ListCapabilities.class)
+            .apply(new ConfigResource());
     for (String id : GlobalCapability.getAllNames()) {
       assertTrue("contains " + id, m.containsKey(id));
       assertEquals(id, m.get(id).id);
       assertNotNull(id + " has name", m.get(id).name);
     }
+
+    String pluginCapability = "gerrit-printHello";
+    assertTrue("contains " + pluginCapability, m.containsKey(pluginCapability));
+    assertEquals(pluginCapability, m.get(pluginCapability).id);
+    assertEquals("Print Hello", m.get(pluginCapability).name);
   }
 }