Use diamond in generic creation where possible

Change-Id: I80b73b653e97904605dc62484a7448f3bfbf7214

server/src/main/java/com/vaadin/server/BootstrapHandler.java

@@ -276,7 +276,7 @@ public abstract class BootstrapHandler extends SynchronizedRequestHandler {
 
             BootstrapContext context = new BootstrapContext(response,
                     new BootstrapFragmentResponse(this, request, session,
-                            uiClass, new ArrayList<Node>(), provider));
+                            uiClass, new ArrayList<>(), provider));
 
             setupMainDiv(context);
 

server/src/main/java/com/vaadin/server/ComponentSizeValidator.java

@@ -716,7 +716,7 @@ public class ComponentSizeValidator implements Serializable {
     public static List<InvalidLayout> validateLayouts(UI ui) {
         List<InvalidLayout> invalidRelativeSizes = ComponentSizeValidator
                 .validateComponentRelativeSizes(ui.getContent(),
-                        new ArrayList<ComponentSizeValidator.InvalidLayout>(),
+                        new ArrayList<>(),
                         null);
 
         // Also check any existing subwindows

server/src/main/java/com/vaadin/ui/GridLayout.java

@@ -1281,7 +1281,7 @@ public class GridLayout extends AbstractLayout
         for (Element e : design.children()) {
             if (e.tagName().equalsIgnoreCase("row")) {
                 rowElements.add(e);
-                rows.add(new HashMap<Integer, Component>());
+                rows.add(new HashMap<>());
 
             }
         }
@@ -1333,7 +1333,7 @@ public class GridLayout extends AbstractLayout
                             + colspan; ++colIndex) {
                         if (rowIndex == rows.size()) {
                             // Rowspan with not enough rows. Fix by adding rows.
-                            rows.add(new HashMap<Integer, Component>());
+                            rows.add(new HashMap<>());
                         }
                         rows.get(rowIndex).put(colIndex + skippedColumns,
                                 child);

server/src/main/java/com/vaadin/ui/renderers/ClickableRenderer.java

@@ -136,7 +136,7 @@ public abstract class ClickableRenderer<T, V> extends AbstractRenderer<T, V> {
                 T item = grid.getDataCommunicator().getKeyMapper().get(rowKey);
                 Column column = grid.getColumn(columnId);
 
-                fireEvent(new RendererClickEvent<T>(grid, item, column,
+                fireEvent(new RendererClickEvent<>(grid, item, column,
                         mouseDetails));
             }
         });

server/src/test/java/com/vaadin/tests/design/DeclarativeTestBase.java

@@ -124,7 +124,7 @@ public abstract class DeclarativeTestBase<T extends Component>
                 System.out.println("No comparator found for " + c.getName()
                         + ". Using introspector.");
             }
-            return new IntrospectorEqualsAsserter<T>(c);
+            return new IntrospectorEqualsAsserter<>(c);
         }
         return comp;
     }