Update server-backed state key generation.

chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos_unittest.cc

Index: chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos_unittest.cc
diff --git a/chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos_unittest.cc b/chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos_unittest.cc
index 0562e5d410ea3a8b00256226b35a30f11b7a5315..b33633042aa872acbf616f3aec22179c928ac22b 100644
--- a/chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos_unittest.cc
+++ b/chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos_unittest.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos.h"
 
+#include <algorithm>
+
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
@@ -261,6 +263,60 @@ TEST_F(DeviceCloudPolicyManagerChromeOSTest, ConsumerDevice) {
   EXPECT_TRUE(manager_->policies().Equals(bundle));
 }
 
+class DeviceCloudPolicyManagerChromeOSStateKeyTest : public testing::Test {
+ protected:
+  DeviceCloudPolicyManagerChromeOSStateKeyTest() {}
+
+  virtual void SetUp() OVERRIDE {
+    chromeos::system::StatisticsProvider::SetTestProvider(
+        &statistics_provider_);

[Joao da Silva, 2014/03/27 15:45:40]

Remove this on TearDown?

[Mattias Nissler (ping if slow), 2014/03/27 16:12:41]

I debated it as it's not strictly needed (i.e. test runner code shouldn't call
into StatisticsProvider), so I decided to leave it out for brevity.

[Joao da Silva, 2014/03/27 16:29:48]

Note that this mock object will remain as the static global testing
StatisticsProvider, so subsequent unit tests may crash if they hit code that
reaches for the StatisticsProvider. I really think it's a good idea to reset it
to NULL.

[Mattias Nissler (ping if slow), 2014/03/27 17:04:08]

Uh, good point. Fixed. Globals suck.

+    EXPECT_CALL(statistics_provider_, GetMachineStatistic(_, _))
+        .WillRepeatedly(Invoke(this,
+                               &DeviceCloudPolicyManagerChromeOSStateKeyTest::
+                                   GetMachineStatistic));
+  }
+
+  bool GetMachineStatistic(const std::string& name, std::string* result) {
+    *result = "fake-" + name;
+    return true;
+  }
+
+ private:
+  chromeos::system::MockStatisticsProvider statistics_provider_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeviceCloudPolicyManagerChromeOSStateKeyTest);
+};
+
+TEST_F(DeviceCloudPolicyManagerChromeOSStateKeyTest, GetDeviceStateKeys) {
+  base::Time current = base::Time::UnixEpoch() + base::TimeDelta::FromDays(100);
+
+  // The correct number of state keys gets returned.
+  std::vector<std::string> state_keys;
+  EXPECT_TRUE(DeviceCloudPolicyManagerChromeOS::GetDeviceStateKeys(
+      current, &state_keys));
+  EXPECT_EQ(DeviceCloudPolicyManagerChromeOS::kDeviceStateKeyFutureQuanta,
+            static_cast<int>(state_keys.size()));
+
+  // All state keys are different.
+  std::set<std::string> state_key_set(state_keys.begin(), state_keys.end());
+  EXPECT_EQ(DeviceCloudPolicyManagerChromeOS::kDeviceStateKeyFutureQuanta,
+            static_cast<int>(state_key_set.size()));
+
+  // Incrementing time results in the state keys rolling forward.
+  int64 step =
+      GG_INT64_C(1)
+      << DeviceCloudPolicyManagerChromeOS::kDeviceStateKeyTimeQuantumPower;
+  current += 2 * base::TimeDelta::FromSeconds(step);
+
+  std::vector<std::string> new_state_keys;
+  EXPECT_TRUE(DeviceCloudPolicyManagerChromeOS::GetDeviceStateKeys(
+      current, &new_state_keys));
+  ASSERT_EQ(DeviceCloudPolicyManagerChromeOS::kDeviceStateKeyFutureQuanta,
+            static_cast<int>(new_state_keys.size()));
+  EXPECT_TRUE(std::equal(state_keys.begin() + 2, state_keys.end(),
+                         new_state_keys.begin()));
+}

[Joao da Silva, 2014/03/27 15:45:40]

Suggestion: verify that a small time increase within the quantum size produces
the same values

[Mattias Nissler (ping if slow), 2014/03/27 16:12:41]

Good idea, done.

+
 class DeviceCloudPolicyManagerChromeOSEnrollmentTest
     : public DeviceCloudPolicyManagerChromeOSTest {
  public: