Remove isolated app code from iOS's chrome_browser_state_io_data.

ios/chrome/browser/browser_state/test_chrome_browser_state_isolated_context.mm

Index: ios/chrome/browser/browser_state/test_chrome_browser_state_isolated_context.mm
diff --git a/ios/chrome/browser/browser_state/test_chrome_browser_state_isolated_context.mm b/ios/chrome/browser/browser_state/test_chrome_browser_state_isolated_context.mm
index 0f23ae5987e18625cbdff7b3e53da03c14a5df8c..7985e0e3bfb778328c8f7607d4c91d34744f0884 100644
--- a/ios/chrome/browser/browser_state/test_chrome_browser_state_isolated_context.mm
+++ b/ios/chrome/browser/browser_state/test_chrome_browser_state_isolated_context.mm
@@ -15,9 +15,7 @@ TestChromeBrowserStateWithIsolatedContext::
                              scoped_ptr<syncable_prefs::PrefServiceSyncable>(),
                              TestingFactories(),
                              RefcountedTestingFactories()),
-      main_context_called_(false),
-      request_context_(new net::TestURLRequestContextGetter(
-          web::WebThread::GetTaskRunnerForThread(web::WebThread::IO))) {}
+      main_context_called_(false) {}
 
 TestChromeBrowserStateWithIsolatedContext::
     ~TestChromeBrowserStateWithIsolatedContext() {}
@@ -36,9 +34,3 @@ TestChromeBrowserStateWithIsolatedContext::GetRequestContext() {
   main_context_called_ = true;
   return TestChromeBrowserState::GetRequestContext();
 }
-
-net::URLRequestContextGetter*
-TestChromeBrowserStateWithIsolatedContext::CreateIsolatedRequestContext(
-    const base::FilePath& partition_path) {
-  return request_context_.get();
-}