update_engine: use ScopedTempDir::GetPath

Upstream versions of libchrome have gotten rid of ScopedTempDir's
inline path method because they wanted to introduce a DCHECK that
helps make sure people create the temp directory before using it.
To avoid introducing a header dependency on the logging header
they took this method out of the header so it wouldn't be inlined.

BUG=b:37434548
TEST=unit tests

Change-Id: If1dcc5e43f54ab32fd43da7b939216a4834548d5
Reviewed-on: https://chromium-review.googlesource.com/882543
Commit-Ready: Eric Caruso <ejcaruso@chromium.org>
Tested-by: Eric Caruso <ejcaruso@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/hardware_chromeos_unittest.cc b/hardware_chromeos_unittest.cc
index a6bad54..162dec4 100644
--- a/hardware_chromeos_unittest.cc
+++ b/hardware_chromeos_unittest.cc
@@ -37,21 +37,22 @@
   void SetUp() override { ASSERT_TRUE(root_dir_.CreateUniqueTempDir()); }
 
   void WriteStatefulConfig(const string& config) {
-    base::FilePath kFile(root_dir_.path().value() + kStatefulPartition +
+    base::FilePath kFile(root_dir_.GetPath().value() + kStatefulPartition +
                          "/etc/update_manager.conf");
     ASSERT_TRUE(base::CreateDirectory(kFile.DirName()));
     ASSERT_TRUE(WriteFileString(kFile.value(), config));
   }
 
   void WriteRootfsConfig(const string& config) {
-    base::FilePath kFile(root_dir_.path().value() + "/etc/update_manager.conf");
+    base::FilePath kFile(root_dir_.GetPath().value() +
+                         "/etc/update_manager.conf");
     ASSERT_TRUE(base::CreateDirectory(kFile.DirName()));
     ASSERT_TRUE(WriteFileString(kFile.value(), config));
   }
 
   // Helper method to call HardwareChromeOS::LoadConfig with the test directory.
   void CallLoadConfig(bool normal_mode) {
-    hardware_.LoadConfig(root_dir_.path().value(), normal_mode);
+    hardware_.LoadConfig(root_dir_.GetPath().value(), normal_mode);
   }
 
   HardwareChromeOS hardware_;