Update assumptions in LoggingRPCSuite and fix missing class name (#9955)

CollectorChrome was renamed about 10 years ago, and sourcemaps are well
supported now, so this test can be adjusted to always handle the
optimized case.

Fixes the recent build failure.

Author: niloc132

user/test/com/google/gwt/user/LoggingRPCSuite.gwt.xml

@@ -19,21 +19,16 @@
   <servlet path='/loggingrpc'
     class='com.google.gwt.user.server.rpc.LoggingRPCTestServiceImpl' />
 
+  <!-- Enabling sourcemaps will stop JUnit.gwt.xml from using emulated stack mode -->
   <set-property name="compiler.useSourceMaps" value="true"/>
+  <!-- This is the default, set explicitly to ensure we are set correctly -->
+  <set-property name="compiler.stackMode" value="native"/>
 
-
-  <!-- Turn off emulation to test non-sourcemap mode -->
-  <set-property name="compiler.stackMode" value="native"/> 
-  <!-- when Chrome is enabled, turn off stack trace emulation -->
-  <set-property name="compiler.stackMode" value="strip"> 
-    <when-property-is name="user.agent" value="safari"/>
-  </set-property>
-
-  <!-- when stack trace stripping is enabled, we need to replace the Null collector 
-       with one that does something -->
-  <replace-with class="com.google.gwt.core.client.impl.StackTraceCreator.CollectorChrome">
+  <!-- When stack trace stripping is enabled, we need to replace the Null collector with one that
+       does something. Not currently in use, see https://github.com/gwtproject/gwt/issues/9956 for
+       more information. -->
+  <replace-with class="com.google.gwt.core.client.impl.StackTraceCreator.CollectorModern">
     <when-type-is class="com.google.gwt.core.client.impl.StackTraceCreator.Collector" />
-    <when-property-is name="compiler.useSourceMaps" value="true" />
+    <when-property-is name="compiler.stackMode" value="strip" />
   </replace-with>
-
 </module>

user/test/com/google/gwt/user/client/rpc/LoggingRPCTest.java

@@ -179,7 +179,7 @@ public void onSuccess(LogRecord record) {
                   break;
                 }
               }
-              assertTrue(found);
+              assertTrue("expected frame found in stack trace", found);
               finishTest();
             }
           });