Use a valid /prefetch argument when launching a process.

chrome/browser/chrome_content_browser_client_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chrome_content_browser_client.h"
 
 #include <map>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 149 matching lines @@
   static const char kFakeGroupName[];
   static const char kDefaultGroupName[];
 
   BlinkSettingsFieldTrialTest()
       : trial_list_(NULL),
         command_line_(base::CommandLine::NO_PROGRAM) {}
 
   void SetUp() override {
     command_line_.AppendSwitchASCII(
         switches::kProcessType, switches::kRendererProcess);
+
+#if defined(OS_WIN)
+    command_line_.AppendArg(switches::kPrefetchArgumentRenderer);

[gab, 2016/01/26 21:40:26]

This is a unittest, I would guess it doesn't go through the DCHECK in main, no?
If so, I'd say don't put it here.

[fdoray, 2016/01/27 20:12:19]

Done.

+#endif  // defined(OS_WIN)
   }
 
   void TearDown() override {
     variations::testing::ClearAllVariationParams();
   }
 
   void CreateFieldTrial(const char* trial_name, const char* group_name) {
     base::FieldTrialList::CreateFieldTrial(trial_name, group_name);
   }
 
@@ skipping 188 matching lines @@
 
   NavigationEntry* entry = browser()->tab_strip_model()->
       GetActiveWebContents()->GetController().GetLastCommittedEntry();
   ASSERT_TRUE(entry != NULL);
   EXPECT_EQ(url_rewritten, entry->GetURL());
   EXPECT_EQ(url_original, entry->GetVirtualURL());
 }
 
 }  // namespace content
 #endif  // !defined(OS_IOS) && !defined(OS_ANDROID)