Fix DefaultMockMvcBuilder fluent API generic type

Changed upper bound of generic parameter for DefaultMockMvcBuilder from
MockMvcBuilder to DefaultMockMvcBuilder to allow for ongoing method
chaining in the fluent API style.

Issue: SPR-10277

Author: Wesley Hall

spring-test-mvc/src/main/java/org/springframework/test/web/servlet/setup/DefaultMockMvcBuilder.java

@@ -42,7 +42,7 @@
  * @author Rob Winch
  * @since 3.2
  */
-public class DefaultMockMvcBuilder<Self extends MockMvcBuilder> extends MockMvcBuilderSupport
+public class DefaultMockMvcBuilder<Self extends DefaultMockMvcBuilder> extends MockMvcBuilderSupport
 		implements MockMvcBuilder {
 
 	private final WebApplicationContext webAppContext;

spring-test-mvc/src/test/java/org/springframework/test/web/servlet/setup/Spr10277Tests.java

@@ -0,0 +1,43 @@
+package org.springframework.test.web.servlet.setup;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.filter.CharacterEncodingFilter;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
+
+/**
+ * Test for SPR-10277 (Multiple method chaining when building MockMvc).
+ *
+ * @author Wesley Hall
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@WebAppConfiguration
+@ContextConfiguration
+public class Spr10277Tests {
+
+    @Autowired
+    private WebApplicationContext wac;
+
+    @Test
+    public void chainMultiple() {
+        MockMvcBuilders
+                .webAppContextSetup(wac)
+                .addFilter(new CharacterEncodingFilter() )
+                .defaultRequest(get("/").contextPath("/mywebapp"))
+                .build();
+    }
+
+    @Configuration
+    @EnableWebMvc
+    static class WebConfig extends WebMvcConfigurerAdapter {
+    }
+}