Alignment of ServerPluginProvider to latest interfaces

Adoption of Optional<T> and removal of name in the 
ServerPluginProvider.

Aligned with the refs/changes/70/56270/3 on Gerrit

Change-Id: Icfe9f1ece3a58002db30d64236daaaf031575ed2

src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginProvider.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginProvider.java b/src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginProvider.java
index 1c46c7b..0651148 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginProvider.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginProvider.java
@@ -58,10 +58,11 @@
   }
 
   @Override
-  public ServerPlugin get(String name, File srcFile, PluginUser pluginUser,
+  public ServerPlugin get(File srcFile, PluginUser pluginUser,
       FileSnapshot snapshot, String pluginCanonicalWebUrl, File pluginDataDir)
       throws InvalidPluginException {
     ScalaPluginScriptEngine scriptEngine = scriptEngineProvider.get();
+    String name = getPluginName(srcFile);
     return new ServerPlugin(name, pluginCanonicalWebUrl, pluginUser, srcFile,
         snapshot, new ScalaPluginScanner(name, srcFile, scriptEngine),
         pluginDataDir, scriptEngine.getClassLoader());

src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginScanner.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginScanner.java b/src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginScanner.java
index 5af869b..e72fc72 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginScanner.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/scripting/scala/ScalaPluginScanner.java
@@ -13,6 +13,7 @@
 // limitations under the License.
 package com.googlesource.gerrit.plugins.scripting.scala;
 
+import com.google.common.base.Optional;
 import com.google.gerrit.server.plugins.AbstractPreloadedPluginScanner;
 import com.google.gerrit.server.plugins.InvalidPluginException;
 import com.google.gerrit.server.plugins.Plugin;
@@ -53,14 +54,14 @@
   }
 
   @Override
-  public <T> T getResource(String resourcePath, Class<? extends T> resourceClass) {
-    return null;
+  public <T> Optional<T> getResource(String resourcePath, Class<? extends T> resourceClass) {
+    return Optional.absent();
   }
 
   @Override
-  public InputStream getResourceInputStream(String resourcePath)
+  public Optional<InputStream> getResourceInputStream(String resourcePath)
       throws IOException {
-    return null;
+    return Optional.absent();
   }
 
   @Override