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..d15f0c037e8b94b7307692473fac7d975df8907b 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"
@@ -81,10 +82,69 @@ 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.
+class ScopedPath {
+  // TODO: By making this more generic we can possibly reused it at

[Paweł Hajdan Jr., 2013/08/26 21:39:49]

nit: TODO should have a username in parentheses. Ideally TODO(bratell), but feel
free to say TODO(phajdan.jr).

See
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=TODO_C...

+  //       other places such as chrome/common/multi_process_lock_unittest.cc.
+ public:
+  // Constructor which sets up the environment to include the path to
+  // third_party/python_26.

[Paweł Hajdan Jr., 2013/08/26 21:39:49]

nit: Don't mention python_26 here as it's supposed to be generic.

+  ScopedPath(const base::FilePath& path_to_add);

[Paweł Hajdan Jr., 2013/08/26 21:39:49]

nit: One-parameter ctros should be marked explicit.

+
+  // 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. If we
+  // haven't then we should also not try to "restore" it in the

[Paweł Hajdan Jr., 2013/08/26 21:39:49]

nit: No need for the "If we haven't" part (up to you though - feel free to keep
if you think it should be there).

+  // destructor.
+  bool path_modified_;
+
+  // This is a local stack based helper object. Copying it would make

[Paweł Hajdan Jr., 2013/08/26 21:39:49]

nit: DISALLOW_COPY_AND_ASSIGN is a common enough macro that it doesn't need a
comment.

+  // no sense and would cause bugs.
+  DISALLOW_COPY_AND_ASSIGN(ScopedPath);
+};
+
+ScopedPath::ScopedPath(const base::FilePath& path_to_add)
+    : environment_(base::Environment::Create()),
+      path_modified_(false) {
+  // Retrieves the old PATH, adds the new path to the end of it and

[Paweł Hajdan Jr., 2013/08/26 21:39:49]

nit: No need for this comment.

+  // then restores the original PATH in the destructor.
+  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_) {

[Paweł Hajdan Jr., 2013/08/26 21:39:49]

nit: I prefer an early return, like:

if (!path_modified_)
  return;

if (old_path_.empty())
  ...

+    if (old_path_.empty())
+      environment_->UnSetVar("PATH");
+    else
+      environment_->SetVar("PATH", old_path_);
+  }
+}
+
 }  // namespace
 
 namespace net {
 
+

[Paweł Hajdan Jr., 2013/08/26 21:39:49]

nit: No need for this empty line.

 bool LocalTestServer::LaunchPython(const base::FilePath& testserver_path) {
   CommandLine python_command(CommandLine::NO_PROGRAM);
   if (!GetPythonCommand(&python_command))
@@ -134,6 +194,15 @@ 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();