Convert ContentMain to take a struct instead of parameters that vary depending on the platform.

content/public/common/main_function_params.h

Index: content/public/common/main_function_params.h
===================================================================
--- content/public/common/main_function_params.h	(revision 255735)
+++ content/public/common/main_function_params.h	(working copy)
@@ -9,8 +9,8 @@
 #ifndef CONTENT_PUBLIC_COMMON_MAIN_FUNCTION_PARAMS_H_
 #define CONTENT_PUBLIC_COMMON_MAIN_FUNCTION_PARAMS_H_
 
+#include "base/callback_forward.h"
 #include "base/command_line.h"
-#include "base/callback_forward.h"
 
 #if defined(OS_WIN)
 namespace sandbox {
@@ -34,13 +34,17 @@
 #elif defined(OS_MACOSX)
         autorelease_pool(NULL),
 #endif
-        ui_task(NULL) {}
+        ui_task(NULL) {
+  }
+
   const CommandLine& command_line;
+
 #if defined(OS_WIN)
   sandbox::SandboxInterfaceInfo* sandbox_info;
 #elif defined(OS_MACOSX)
   base::mac::ScopedNSAutoreleasePool* autorelease_pool;
 #endif
+
   // Used by InProcessBrowserTest. If non-null BrowserMain schedules this
   // task to run on the MessageLoop and BrowserInit is not invoked.
   base::Closure* ui_task;