[DevTools] Improve context and target naming.

third_party/WebKit/LayoutTests/http/tests/inspector/console-test.js

 var initialize_ConsoleTest = function() {
 
 InspectorTest.preloadModule("source_frame");
 InspectorTest.preloadPanel("console");
 
 InspectorTest.selectMainExecutionContext = function()
 {
     var executionContexts = InspectorTest.mainTarget.runtimeModel.executionContexts();
     for (var context of executionContexts) {
         if (context.isDefault) {
@@ skipping 378 matching lines @@
     var promise = new Promise((fullfill) => callback = fullfill);
     InspectorTest.waitUntilNthMessageReceived(count, callback);
     return promise;
 }
 
 InspectorTest.changeExecutionContext = function(namePrefix)
 {
     var selector = Console.ConsoleView.instance()._consoleContextSelector._selectElement;
     var option = selector.firstChild;
     while (option) {
-        if (option.textContent && option.textContent.startsWith(namePrefix))
+        if (option.textContent && option.textContent.trim().startsWith(namePrefix))
             break;
         option = option.nextSibling;
     }
     if (!option) {
         InspectorTest.addResult("FAILED: context with prefix: "  + namePrefix + " not found in the context list");
         return;
     }
     option.selected = true;
     Console.ConsoleView.instance()._consoleContextSelector._executionContextChanged();
 }
 
 InspectorTest.waitForConsoleMessages = function(expectedCount, callback)
 {
     var consoleView = Console.ConsoleView.instance();
     checkAndReturn();
 
     function checkAndReturn()
     {
         if (consoleView._visibleViewMessages.length === expectedCount) {
             InspectorTest.addResult("Message count: " + expectedCount);
             callback();
         } else {
             InspectorTest.addSniffer(consoleView, "_messageAppendedForTests", checkAndReturn);
         }
     }
 }
 
 }