PlatformAppApiTest class should not enable experimental APIs by default

chrome/browser/extensions/api/dns/dns_apitest.cc

Index: chrome/browser/extensions/api/dns/dns_apitest.cc
diff --git a/chrome/browser/extensions/api/dns/dns_apitest.cc b/chrome/browser/extensions/api/dns/dns_apitest.cc
index e215a64941dbeeef3518680f7e3b3c11380b9b53..a4c5ad0f8795d2a58854651e1235147b665ad291 100644
--- a/chrome/browser/extensions/api/dns/dns_apitest.cc
+++ b/chrome/browser/extensions/api/dns/dns_apitest.cc
@@ -9,6 +9,7 @@
 #include "chrome/browser/extensions/api/dns/mock_host_resolver_creator.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/browser/extensions/extension_function_test_utils.h"
+#include "chrome/common/chrome_switches.h"
 #include "net/base/mock_host_resolver.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
@@ -18,12 +19,17 @@ using extension_function_test_utils::RunFunctionAndReturnSingleResult;
 
 namespace {
 
-class DnsApiTest : public PlatformAppApiTest {
+class DnsApiTest : public ExtensionApiTest {
  public:
   DnsApiTest() : resolver_event_(true, false),
                  resolver_creator_(new extensions::MockHostResolverCreator()) {
   }
 
+  virtual void SetUpCommandLine(CommandLine* command_line) OVERRIDE {
+    ExtensionApiTest::SetUpCommandLine(command_line);
+    command_line->AppendSwitch(switches::kEnableExperimentalExtensionApis);
+  }
+
   void SetUpOnMainThread() OVERRIDE {
     extensions::HostResolverWrapper::GetInstance()->SetHostResolverForTesting(
         resolver_creator_->CreateMockHostResolver());