chromeos: Wait for service to be available when getting system salt

Add CryptohomeClient::WaitForServiceToBeAvailable().
Use WaitForServiceToBeAvailable() from SystemSaltGetter.

BUG=141009
R=satorux@chromium.org

Review URL: https://codereview.chromium.org/34303002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230067 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 47 insertions, 1 deletions

diff --git a/chromeos/dbus/cryptohome_client.cc b/chromeos/dbus/cryptohome_client.cc
index 79a6561..ca2d48a 100644
--- a/chromeos/dbus/cryptohome_client.cc
+++ b/chromeos/dbus/cryptohome_client.cc
@@ -45,6 +45,12 @@ class CryptohomeClientImpl : public CryptohomeClient {
   }
 
   // CryptohomeClient override.
+  virtual void WaitForServiceToBeAvailable(
+      const WaitForServiceToBeAvailableCallback& callback) OVERRIDE {
+    proxy_->WaitForServiceToBeAvailable(callback);
+  }
+
+  // CryptohomeClient override.
   virtual void IsMounted(const BoolDBusMethodCallback& callback) OVERRIDE {
     dbus::MethodCall method_call(cryptohome::kCryptohomeInterface,
                                  cryptohome::kCryptohomeIsMounted);
diff --git a/chromeos/dbus/cryptohome_client.h b/chromeos/dbus/cryptohome_client.h
index cc4b9d7..036cf64 100644
--- a/chromeos/dbus/cryptohome_client.h
+++ b/chromeos/dbus/cryptohome_client.h
@@ -35,6 +35,9 @@ class CHROMEOS_EXPORT CryptohomeClient : public DBusClient {
       AsyncCallStatusWithDataHandler;
   // A callback to handle responses of AsyncXXX methods.
   typedef base::Callback<void(int async_id)> AsyncMethodCallback;
+  // A callback for WaitForServiceToBeAvailable().
+  typedef base::Callback<void(bool service_is_ready)>
+      WaitForServiceToBeAvailableCallback;
   // A callback to handle responses of Pkcs11GetTpmTokenInfo method.  The result
   // of the D-Bus call is in |call_status|.  On success, |label| holds the
   // PKCS #11 token label.  This is not useful in practice to identify a token
@@ -73,6 +76,10 @@ class CHROMEOS_EXPORT CryptohomeClient : public DBusClient {
   // Resets AsyncCallStatus signal handlers.
   virtual void ResetAsyncCallStatusHandlers() = 0;
 
+  // Runs the callback as soon as the service becomes available.
+  virtual void WaitForServiceToBeAvailable(
+      const WaitForServiceToBeAvailableCallback& callback) = 0;
+
   // Calls IsMounted method and returns true when the call succeeds.
   virtual void IsMounted(const BoolDBusMethodCallback& callback) = 0;
 
diff --git a/chromeos/dbus/fake_cryptohome_client.cc b/chromeos/dbus/fake_cryptohome_client.cc
index 7b40854..d23be71 100644
--- a/chromeos/dbus/fake_cryptohome_client.cc
+++ b/chromeos/dbus/fake_cryptohome_client.cc
@@ -13,7 +13,8 @@
 namespace chromeos {
 
 FakeCryptohomeClient::FakeCryptohomeClient()
-    : async_call_id_(1),
+    : service_is_available_(true),
+      async_call_id_(1),
       tpm_is_ready_counter_(0),
       unmount_result_(true),
       locked_(false),
@@ -36,6 +37,16 @@ void FakeCryptohomeClient::ResetAsyncCallStatusHandlers() {
   async_call_status_data_handler_.Reset();
 }
 
+void FakeCryptohomeClient::WaitForServiceToBeAvailable(
+    const WaitForServiceToBeAvailableCallback& callback) {
+  if (service_is_available_) {
+    base::MessageLoop::current()->PostTask(FROM_HERE,
+                                           base::Bind(callback, true));
+  } else {
+    pending_wait_for_service_to_be_available_callbacks_.push_back(callback);
+  }
+}
+
 void FakeCryptohomeClient::IsMounted(
     const BoolDBusMethodCallback& callback) {
   base::MessageLoop::current()->PostTask(
@@ -368,6 +379,16 @@ void FakeCryptohomeClient::TpmAttestationSetKeyPayload(
       FROM_HERE, base::Bind(callback, DBUS_METHOD_CALL_SUCCESS, false));
 }
 
+void FakeCryptohomeClient::SetServiceIsAvailable(bool is_available) {
+  service_is_available_ = is_available;
+  if (is_available) {
+    std::vector<WaitForServiceToBeAvailableCallback> callbacks;
+    callbacks.swap(pending_wait_for_service_to_be_available_callbacks_);
+    for (size_t i = 0; i < callbacks.size(); ++i)
+      callbacks[i].Run(is_available);
+  }
+}
+
 // static
 std::vector<uint8> FakeCryptohomeClient::GetStubSystemSalt() {
   const char kStubSystemSalt[] = "stub_system_salt";
diff --git a/chromeos/dbus/fake_cryptohome_client.h b/chromeos/dbus/fake_cryptohome_client.h
index 4f045ec..3c960e8 100644
--- a/chromeos/dbus/fake_cryptohome_client.h
+++ b/chromeos/dbus/fake_cryptohome_client.h
@@ -23,6 +23,8 @@ class CHROMEOS_EXPORT FakeCryptohomeClient : public CryptohomeClient {
       const AsyncCallStatusHandler& handler,
       const AsyncCallStatusWithDataHandler& data_handler) OVERRIDE;
   virtual void ResetAsyncCallStatusHandlers() OVERRIDE;
+  virtual void WaitForServiceToBeAvailable(
+      const WaitForServiceToBeAvailableCallback& callback) OVERRIDE;
   virtual void IsMounted(const BoolDBusMethodCallback& callback) OVERRIDE;
   virtual bool Unmount(bool* success) OVERRIDE;
   virtual void AsyncCheckKey(const std::string& username,
@@ -151,6 +153,10 @@ class CHROMEOS_EXPORT FakeCryptohomeClient : public CryptohomeClient {
       const std::string& payload,
       const BoolDBusMethodCallback& callback) OVERRIDE;
 
+  // Changes the behavior of WaitForServiceToBeAvailable(). This method runs
+  // pending callbacks if is_available is true.
+  void SetServiceIsAvailable(bool is_available);
+
   // Sets the unmount result of Unmount() call.
   void set_unmount_result(bool result) {
     unmount_result_= result;
@@ -169,12 +175,16 @@ class CHROMEOS_EXPORT FakeCryptohomeClient : public CryptohomeClient {
   void ReturnAsyncMethodResultInternal(const AsyncMethodCallback& callback,
                                        bool returns_data);
 
+  bool service_is_available_;
   int async_call_id_;
   AsyncCallStatusHandler async_call_status_handler_;
   AsyncCallStatusWithDataHandler async_call_status_data_handler_;
   int tpm_is_ready_counter_;
   bool unmount_result_;
 
+  std::vector<WaitForServiceToBeAvailableCallback>
+      pending_wait_for_service_to_be_available_callbacks_;
+
   // A stub store for InstallAttributes, mapping an attribute name to the
   // associated data blob. Used to implement InstallAttributesSet and -Get.
   std::map<std::string, std::vector<uint8> > install_attrs_;
diff --git a/chromeos/dbus/mock_cryptohome_client.h b/chromeos/dbus/mock_cryptohome_client.h
index 8cb4c6b..cdb1ad8 100644
--- a/chromeos/dbus/mock_cryptohome_client.h
+++ b/chromeos/dbus/mock_cryptohome_client.h
@@ -22,6 +22,8 @@ class MockCryptohomeClient : public CryptohomeClient {
                void(const AsyncCallStatusHandler& handler,
                     const AsyncCallStatusWithDataHandler& data_handler));
   MOCK_METHOD0(ResetAsyncCallStatusHandlers, void());
+  MOCK_METHOD1(WaitForServiceToBeAvailable,
+               void(const WaitForServiceToBeAvailableCallback& callback));
   MOCK_METHOD1(IsMounted, void(const BoolDBusMethodCallback& callback));
   MOCK_METHOD1(Unmount, bool(bool* success));
   MOCK_METHOD3(AsyncCheckKey,