Use a valid /prefetch argument when launching a process.

content/browser/gpu/gpu_process_host.cc

 // Copyright (c) 2012 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 "content/browser/gpu/gpu_process_host.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 1010 matching lines @@
 
   base::FilePath exe_path = ChildProcessHost::GetChildPath(child_flags);
   if (exe_path.empty())
     return false;
 
   base::CommandLine* cmd_line = new base::CommandLine(exe_path);
 #endif
   cmd_line->AppendSwitchASCII(switches::kProcessType, switches::kGpuProcess);
   cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id);
 
+#if defined(OS_WIN)
+  if (GetContentClient()->browser()->ShouldUseWindowsPrefetchArgument())
+    cmd_line->AppendArg(switches::kPrefetchArgumentGpu);
+#endif  // defined(OS_WIN)
+
   if (kind_ == GPU_PROCESS_KIND_UNSANDBOXED)
     cmd_line->AppendSwitch(switches::kDisableGpuSandbox);
 
   // If you want a browser command-line switch passed to the GPU process
   // you need to add it to |kSwitchNames| at the beginning of this file.
   cmd_line->CopySwitchesFrom(browser_command_line, kSwitchNames,
                              arraysize(kSwitchNames));
   cmd_line->CopySwitchesFrom(
       browser_command_line, switches::kGpuSwitches, switches::kNumGpuSwitches);
   cmd_line->CopySwitchesFrom(
@@ skipping 180 matching lines @@
   TRACE_EVENT0("gpu", "GpuProcessHost::OnCacheShader");
   ClientIdToShaderCacheMap::iterator iter =
       client_id_to_shader_cache_.find(client_id);
   // If the cache doesn't exist then this is an off the record profile.
   if (iter == client_id_to_shader_cache_.end())
     return;
   iter->second->Cache(GetShaderPrefixKey() + ":" + key, shader);
 }
 
 }  // namespace content