Move AlterEnvironment to base/environment.h, implement on Windows.

content/public/browser/utility_process_host.h

Index: content/public/browser/utility_process_host.h
diff --git a/content/public/browser/utility_process_host.h b/content/public/browser/utility_process_host.h
index 4c7e192627602dcf65390da51d2abb1eeaba3018..1a8201b195a5878c67f9a83505d8bbc5f202d3cc 100644
--- a/content/public/browser/utility_process_host.h
+++ b/content/public/browser/utility_process_host.h
@@ -5,7 +5,7 @@
 #ifndef CONTENT_PUBLIC_BROWSER_UTILITY_PROCESS_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_UTILITY_PROCESS_HOST_H_
 
-#include "base/process/launch.h"
+#include "base/environment.h"
 #include "content/common/content_export.h"
 #include "ipc/ipc_sender.h"
 
@@ -64,7 +64,7 @@ class UtilityProcessHost : public IPC::Sender,
   virtual const ChildProcessData& GetData() = 0;
 
 #if defined(OS_POSIX)
-  virtual void SetEnv(const base::EnvironmentVector& env) = 0;
+  virtual void SetEnv(const base::EnvironmentMap& env) = 0;
 #endif
 };