update_engine: Update libchrome APIS to r456626.

The new libchrome has been ported from Chromium and some APIs
have changed. Make necessary changes at call sites.

BUG=chromium:724678
CQ-DEPEND=CL:480928
Test: Build.

Change-Id: I4dbaea4a2a19031375a8bf2415645a4f226dab57
diff --git a/common/hwid_override_unittest.cc b/common/hwid_override_unittest.cc
index 26ef30a..35e6438 100644
--- a/common/hwid_override_unittest.cc
+++ b/common/hwid_override_unittest.cc
@@ -32,7 +32,7 @@
 
   void SetUp() override {
     ASSERT_TRUE(tempdir_.CreateUniqueTempDir());
-    ASSERT_TRUE(base::CreateDirectory(tempdir_.path().Append("etc")));
+    ASSERT_TRUE(base::CreateDirectory(tempdir_.GetPath().Append("etc")));
   }
 
  protected:
@@ -46,22 +46,24 @@
   std::string expected_hwid("expected");
   std::string keyval(HwidOverride::kHwidOverrideKey);
   keyval += ("=" + expected_hwid);
-  ASSERT_EQ(base::WriteFile(tempdir_.path().Append("etc/lsb-release"),
-                            keyval.c_str(), keyval.length()),
+  ASSERT_EQ(base::WriteFile(tempdir_.GetPath().Append("etc/lsb-release"),
+                            keyval.c_str(),
+                            keyval.length()),
             static_cast<int>(keyval.length()));
-  EXPECT_EQ(expected_hwid, HwidOverride::Read(tempdir_.path()));
+  EXPECT_EQ(expected_hwid, HwidOverride::Read(tempdir_.GetPath()));
 }
 
 TEST_F(HwidOverrideTest, ReadNothing) {
   std::string keyval("SOMETHING_ELSE=UNINTERESTING");
-  ASSERT_EQ(base::WriteFile(tempdir_.path().Append("etc/lsb-release"),
-                            keyval.c_str(), keyval.length()),
+  ASSERT_EQ(base::WriteFile(tempdir_.GetPath().Append("etc/lsb-release"),
+                            keyval.c_str(),
+                            keyval.length()),
             static_cast<int>(keyval.length()));
-  EXPECT_EQ(std::string(), HwidOverride::Read(tempdir_.path()));
+  EXPECT_EQ(std::string(), HwidOverride::Read(tempdir_.GetPath()));
 }
 
 TEST_F(HwidOverrideTest, ReadFailure) {
-  EXPECT_EQ(std::string(), HwidOverride::Read(tempdir_.path()));
+  EXPECT_EQ(std::string(), HwidOverride::Read(tempdir_.GetPath()));
 }
 
 }  // namespace chromeos_update_engine