Remove hard dependency on bundled python_26 in tests

net/test/spawned_test_server/local_test_server_win.cc

Index: net/test/spawned_test_server/local_test_server_win.cc
diff --git a/net/test/spawned_test_server/local_test_server_win.cc b/net/test/spawned_test_server/local_test_server_win.cc
index fd26483ed477b37698538f1f2b609e7d79b343f2..7a36c489300ac719270ae5112e4a7031c89ee397 100644
--- a/net/test/spawned_test_server/local_test_server_win.cc
+++ b/net/test/spawned_test_server/local_test_server_win.cc
@@ -10,6 +10,7 @@
 #include "base/base_paths.h"
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/environment.h"
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
 #include "base/path_service.h"
@@ -81,6 +82,60 @@ bool ReadData(HANDLE read_fd, HANDLE write_fd,
   return true;
 }
 
+// Class that sets up a temporary path that includes the supplied path
+// at the end.
+//
+// TODO(bratell): By making this more generic we can possibly reuse
+//                it at other places such as
+//                chrome/common/multi_process_lock_unittest.cc.
+class ScopedPath {
+ public:
+  // Constructor which sets up the environment to include the path to
+  // |path_to_add|.
+  explicit ScopedPath(const base::FilePath& path_to_add);
+
+  // Destructor that restores the path that were active when the
+  // object was constructed.
+  ~ScopedPath();
+
+ private:
+  // The PATH environment variable before it was changed or an empty
+  // string if there was no PATH environment variable.
+  std::string old_path_;
+
+  // The helper object that allows us to read and set environment
+  // variables more easily.
+  scoped_ptr<base::Environment> environment_;
+
+  // A flag saying if we have actually modified the environment.
+  bool path_modified_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedPath);
+};
+
+ScopedPath::ScopedPath(const base::FilePath& path_to_add)
+    : environment_(base::Environment::Create()),
+      path_modified_(false) {
+  environment_->GetVar("PATH", &old_path_);
+
+  std::string new_value = old_path_;
+  if (!new_value.empty())
+    new_value += ";";
+
+  new_value += WideToUTF8(path_to_add.value());
+
+  path_modified_ = environment_->SetVar("PATH", new_value);
+}
+
+ScopedPath::~ScopedPath() {
+  if (!path_modified_)
+    return;
+  if (old_path_.empty())
+    environment_->UnSetVar("PATH");
+  else
+    environment_->SetVar("PATH", old_path_);
+}
+
 }  // namespace
 
 namespace net {
@@ -134,6 +189,15 @@ bool LocalTestServer::LaunchPython(const base::FilePath& testserver_path) {
     return false;
   }
 
+  // Add our internal python to the path so it can be used if there is
+  // no system python.
+  base::FilePath python_dir;
+  if (!PathService::Get(base::DIR_SOURCE_ROOT, &python_dir)) {
+    LOG(ERROR) << "Could not locate source root directory.";
+    return false;
+  }
+  python_dir = python_dir.AppendASCII("third_party").AppendASCII("python_26");
+  ScopedPath python_path(python_dir);
   base::LaunchOptions launch_options;
   launch_options.inherit_handles = true;
   launch_options.job_handle = job_handle_.Get();