AU: Don't allow deltas if the rootfs track is different than the request track.

omaha_request_params_unittest.cc

Index: omaha_request_params_unittest.cc
diff --git a/omaha_request_params_unittest.cc b/omaha_request_params_unittest.cc
index 77d01d2ce7435f8325b5278aaf09430e45dce748..fdbf96e91d470a5a6d2698e3a88633f494397143 100644
--- a/omaha_request_params_unittest.cc
+++ b/omaha_request_params_unittest.cc
@@ -274,11 +274,37 @@ TEST_F(OmahaRequestDeviceParamsTest, OverrideTest) {
   EXPECT_EQ("0.2.2.3", out.app_version);
   EXPECT_EQ("en-US", out.app_lang);
   EXPECT_EQ("", out.hardware_class);
-  EXPECT_TRUE(out.delta_okay);
+  EXPECT_FALSE(out.delta_okay);
   EXPECT_EQ("bartrack", out.app_track);
   EXPECT_EQ("http://www.google.com", out.update_url);
 }
 
+TEST_F(OmahaRequestDeviceParamsTest, OverrideSameTrackTest) {
+  ASSERT_TRUE(WriteFileString(
+      kTestDir + "/etc/lsb-release",
+      "CHROMEOS_RELEASE_BOARD=arm-generic\n"
+      "CHROMEOS_RELEASE_FOO=bar\n"
+      "CHROMEOS_RELEASE_VERSION=0.2.2.3\n"
+      "CHROMEOS_RELEASE_TRACK=footrack\n"
+      "CHROMEOS_AUSERVER=http://www.google.com"));
+  ASSERT_TRUE(WriteFileString(
+      kTestDir + utils::kStatefulPartition + "/etc/lsb-release",
+      "CHROMEOS_RELEASE_BOARD=x86-generic\n"
+      "CHROMEOS_RELEASE_TRACK=footrack"));
+  OmahaRequestParams out;
+  EXPECT_TRUE(DoTest(&out, "", ""));
+  EXPECT_EQ("Chrome OS", out.os_platform);
+  EXPECT_EQ(string("0.2.2.3_") + GetMachineType(), out.os_sp);
+  EXPECT_EQ("x86-generic", out.os_board);
+  EXPECT_EQ("{87efface-864d-49a5-9bb3-4b050a7c227a}", out.app_id);
+  EXPECT_EQ("0.2.2.3", out.app_version);
+  EXPECT_EQ("en-US", out.app_lang);
+  EXPECT_EQ("", out.hardware_class);
+  EXPECT_TRUE(out.delta_okay);
+  EXPECT_EQ("footrack", out.app_track);
+  EXPECT_EQ("http://www.google.com", out.update_url);
+}
+
 TEST_F(OmahaRequestDeviceParamsTest, SetTrackSimpleTest) {
   ASSERT_TRUE(WriteFileString(
       kTestDir + "/etc/lsb-release",