Make nt_registry Create/OpenRegKey return a scoped object

chrome_elf/blacklist/blacklist.cc

Index: chrome_elf/blacklist/blacklist.cc
diff --git a/chrome_elf/blacklist/blacklist.cc b/chrome_elf/blacklist/blacklist.cc
index 05d917fb6db8a32295d0c2f7a9ad96e65a195990..19df821b63515fde9281155b0db3a3ae404d07c1 100644
--- a/chrome_elf/blacklist/blacklist.cc
+++ b/chrome_elf/blacklist/blacklist.cc
@@ -101,16 +101,16 @@ __declspec(allocate(".oldntmap"))
 #endif
 
 bool LeaveSetupBeacon() {
-  HANDLE key_handle = INVALID_HANDLE_VALUE;
+  nt::ScopedHANDLE key_handle = nt::CreateRegKey(
+      nt::HKCU, kRegistryBeaconPath, KEY_QUERY_VALUE | KEY_SET_VALUE);
 
-  if (!nt::CreateRegKey(nt::HKCU, kRegistryBeaconPath,
-                        KEY_QUERY_VALUE | KEY_SET_VALUE, &key_handle))
+  if (!key_handle.is_valid())
     return false;
 
   DWORD blacklist_state = BLACKLIST_STATE_MAX;
-  if (!nt::QueryRegValueDWORD(key_handle, kBeaconState, &blacklist_state) ||
+  if (!nt::QueryRegValueDWORD(key_handle.get(), kBeaconState,
+                              &blacklist_state) ||
       blacklist_state == BLACKLIST_DISABLED) {
-    nt::CloseRegKey(key_handle);
     return false;
   }
 
@@ -120,9 +120,9 @@ bool LeaveSetupBeacon() {
   if (blacklist_state == BLACKLIST_ENABLED) {
     // If the blacklist succeeded on the previous run reset the failure
     // counter.  Then update the beacon state.
-    if (nt::SetRegValueDWORD(key_handle, kBeaconAttemptCount,
+    if (nt::SetRegValueDWORD(key_handle.get(), kBeaconAttemptCount,
                              static_cast<DWORD>(0))) {
-      if (nt::SetRegValueDWORD(key_handle, kBeaconState,
+      if (nt::SetRegValueDWORD(key_handle.get(), kBeaconState,
                                BLACKLIST_SETUP_RUNNING))
         success = true;
     }
@@ -132,47 +132,42 @@ bool LeaveSetupBeacon() {
     // failed and skip setting up the blacklist.
     DWORD attempt_count = 0;
 
-    nt::QueryRegValueDWORD(key_handle, blacklist::kBeaconAttemptCount,
+    nt::QueryRegValueDWORD(key_handle.get(), blacklist::kBeaconAttemptCount,
                            &attempt_count);
     ++attempt_count;
-    nt::SetRegValueDWORD(key_handle, blacklist::kBeaconAttemptCount,
+    nt::SetRegValueDWORD(key_handle.get(), blacklist::kBeaconAttemptCount,
                          attempt_count);
 
     if (attempt_count >= blacklist::kBeaconMaxAttempts) {
       blacklist_state = blacklist::BLACKLIST_SETUP_FAILED;
-      nt::SetRegValueDWORD(key_handle, blacklist::kBeaconState,
+      nt::SetRegValueDWORD(key_handle.get(), blacklist::kBeaconState,
                            blacklist_state);
     }
   }
 
-  nt::CloseRegKey(key_handle);
   return success;
 }
 
 bool ResetBeacon() {
-  HANDLE key_handle = INVALID_HANDLE_VALUE;
-
-  if (!nt::CreateRegKey(nt::HKCU, kRegistryBeaconPath,
-                        KEY_QUERY_VALUE | KEY_SET_VALUE, &key_handle))
+  nt::ScopedHANDLE key_handle = nt::CreateRegKey(
+      nt::HKCU, kRegistryBeaconPath, KEY_QUERY_VALUE | KEY_SET_VALUE);
+  if (!key_handle.is_valid())
     return false;
 
   DWORD blacklist_state = BLACKLIST_STATE_MAX;
-  if (!nt::QueryRegValueDWORD(key_handle, kBeaconState, &blacklist_state)) {
-    nt::CloseRegKey(key_handle);
+  if (!nt::QueryRegValueDWORD(key_handle.get(), kBeaconState, &blacklist_state))
     return false;
-  }
 
   // Reaching this point with the setup running state means the setup did not
   // crash, so we reset to enabled.  Any other state indicates that setup was
   // skipped; in that case we leave the state alone for later recording.
   if (blacklist_state == BLACKLIST_SETUP_RUNNING) {
-    if (!nt::SetRegValueDWORD(key_handle, kBeaconState, BLACKLIST_ENABLED)) {
-      nt::CloseRegKey(key_handle);
+    if (!nt::SetRegValueDWORD(key_handle.get(), kBeaconState,
+                              BLACKLIST_ENABLED)) {
       return false;
     }
   }
 
-  nt::CloseRegKey(key_handle);
   return true;
 }