Make XR browser tests use executable-relative paths

Makes the environment variable paths set by XR browser tests relative
to the test binary's location instead of the current working directory.

This makes the tests runnable from any directory instead of only from
the output directory.

Bug: 912392
Change-Id: I0f6ef8e2019add1457807b3d645d18e6b413b1de
Reviewed-on: https://chromium-review.googlesource.com/c/1367101Reviewed-by: Bill Orr <billorr@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614742}

chrome/browser/vr/test/xr_browser_test.cc

@@ -4,6 +4,7 @@
 
 #include <cstring>
 
+#include "base/base_paths.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
@@ -11,6 +12,7 @@
 #include "base/environment.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
+#include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/threading/platform_thread.h"
@@ -43,25 +45,39 @@ XrBrowserTestBase::XrBrowserTestBase() : env_(base::Environment::Create()) {}
 
 XrBrowserTestBase::~XrBrowserTestBase() = default;
 
-// We need an std::string that is an absolute file path, which requires
-// platform-specific logic since Windows uses std::wstring instead of
-// std::string for FilePaths, but SetVar only accepts std::string.
+// Returns an std::string consisting of the given path relative to the test
+// executable's path, e.g. if the executable is in out/Debug and the given path
+// is "test", the returned string should be out/Debug/test.
+std::string MakeExecutableRelative(const char* path) {
+  base::FilePath executable_path;
+  EXPECT_TRUE(
+      base::PathService::Get(base::BasePathKey::FILE_EXE, &executable_path));
+  executable_path = executable_path.DirName();
+  // We need an std::string that is an absolute file path, which requires
+  // platform-specific logic since Windows uses std::wstring instead of
+  // std::string for FilePaths, but SetVar only accepts std::string.
 #ifdef OS_WIN
-#define MAKE_ABSOLUTE(x) \
-  base::WideToUTF8(      \
-      base::MakeAbsoluteFilePath(base::FilePath(base::UTF8ToWide(x))).value())
+  return base::WideToUTF8(
+      base::MakeAbsoluteFilePath(
+          executable_path.Append(base::FilePath(base::UTF8ToWide(path))))
+          .value());
 #else
-#define MAKE_ABSOLUTE(x) base::MakeAbsoluteFilePath(base::FilePath(x)).value()
+  return base::MakeAbsoluteFilePath(
+             executable_path.Append(base::FilePath(path)))
+      .value();
 #endif
+}
 
 void XrBrowserTestBase::SetUp() {
   // Set the environment variable to use the mock OpenVR client.
-  EXPECT_TRUE(env_->SetVar(kVrOverrideEnvVar, MAKE_ABSOLUTE(kVrOverrideVal)))
-      << "Failed to set OpenVR mock client location environment variable";
   EXPECT_TRUE(
-      env_->SetVar(kVrConfigPathEnvVar, MAKE_ABSOLUTE(kVrConfigPathVal)))
+      env_->SetVar(kVrOverrideEnvVar, MakeExecutableRelative(kVrOverrideVal)))
+      << "Failed to set OpenVR mock client location environment variable";
+  EXPECT_TRUE(env_->SetVar(kVrConfigPathEnvVar,
+                           MakeExecutableRelative(kVrConfigPathVal)))
       << "Failed to set OpenVR config location environment variable";
-  EXPECT_TRUE(env_->SetVar(kVrLogPathEnvVar, MAKE_ABSOLUTE(kVrLogPathVal)))
+  EXPECT_TRUE(
+      env_->SetVar(kVrLogPathEnvVar, MakeExecutableRelative(kVrLogPathVal)))
       << "Failed to set OpenVR log location environment variable";
 
   // Set any command line flags that subclasses have set, e.g. enabling WebVR