Fix build warnings.

PiperOrigin-RevId: 877501913

internal/platform/BUILD

@@ -128,6 +128,7 @@ cc_library(
     ],
     deps = [
         ":base",
+        "@com_google_absl//absl/base:core_headers",
         "@com_google_absl//absl/container:flat_hash_set",
         "@com_google_absl//absl/functional:any_invocable",
         "@com_google_absl//absl/synchronization",

internal/platform/cancellation_flag.cc

@@ -13,7 +13,10 @@
 // limitations under the License.
 
 #include "internal/platform/cancellation_flag.h"
+#include <memory>
 
+#include "absl/container/flat_hash_set.h"
+#include "absl/synchronization/mutex.h"
 #include "internal/platform/feature_flags.h"
 
 namespace nearby {
@@ -28,7 +31,7 @@ CancellationFlag::CancellationFlag(bool cancelled) {
 }
 
 CancellationFlag::~CancellationFlag() {
-  absl::MutexLock lock(*mutex_.get());
+  absl::MutexLock lock(*mutex_);
   listeners_.clear();
 }
 
@@ -40,7 +43,7 @@ void CancellationFlag::Cancel() {
 
   absl::flat_hash_set<CancelListener *> listeners;
   {
-    absl::MutexLock lock(*mutex_.get());
+    absl::MutexLock lock(*mutex_);
     if (cancelled_) {
       // Someone already cancelled. Return immediately.
       return;
@@ -62,14 +65,14 @@ void CancellationFlag::Uncancel() {
   }
 
   {
-    absl::MutexLock lock(*mutex_.get());
+    absl::MutexLock lock(*mutex_);
     assert(cancelled_);
     cancelled_ = false;
   }
 }
 
 bool CancellationFlag::Cancelled() const {
-  absl::MutexLock lock(*mutex_.get());
+  absl::MutexLock lock(*mutex_);
 
   // Return false as no-op if feature flag is not enabled.
   if (!FeatureFlags::GetInstance().GetFlags().enable_cancellation_flag) {
@@ -80,13 +83,13 @@ bool CancellationFlag::Cancelled() const {
 }
 
 void CancellationFlag::RegisterOnCancelListener(CancelListener *listener) {
-  absl::MutexLock lock(*mutex_.get());
+  absl::MutexLock lock(*mutex_);
 
   listeners_.emplace(listener);
 }
 
 void CancellationFlag::UnregisterOnCancelListener(CancelListener *listener) {
-  absl::MutexLock lock(*mutex_.get());
+  absl::MutexLock lock(*mutex_);
 
   listeners_.erase(listener);
 }

internal/platform/cancellation_flag.h

@@ -17,6 +17,7 @@
 
 #include <memory>
 
+#include "absl/base/thread_annotations.h"
 #include "absl/container/flat_hash_set.h"
 #include "absl/functional/any_invocable.h"
 #include "absl/synchronization/mutex.h"
@@ -74,7 +75,7 @@ class CancellationFlag {
       ABSL_LOCKS_EXCLUDED(mutex_);
 
   int CancelListenersSize() const ABSL_LOCKS_EXCLUDED(mutex_) {
-    absl::MutexLock lock(mutex_.get());
+    absl::MutexLock lock(*mutex_);
     return listeners_.size();
   }
 

internal/platform/feature_flags.h

@@ -126,13 +126,13 @@ class FeatureFlags {
     return *instance;
   }
 
-  const Flags& GetFlags() const ABSL_LOCKS_EXCLUDED(mutex_) {
-    absl::ReaderMutexLock lock(&mutex_);
-    return flags_;
+  static FeatureFlags& GetMutableInstanceForTesting() {
+    return const_cast<FeatureFlags&>(GetInstance());
   }
 
-  static Flags& GetMutableFlagsForTesting() {
-    return const_cast<FeatureFlags&>(GetInstance()).flags_;
+  Flags GetFlags() const ABSL_LOCKS_EXCLUDED(mutex_) {
+    absl::ReaderMutexLock lock(mutex_);
+    return flags_;
   }
 
   // SetFlags for feature controlling

internal/platform/feature_flags_test.cc

@@ -28,8 +28,8 @@ constexpr FeatureFlags::Flags kTestFeatureFlags{
 TEST(FeatureFlagsTest, CastUpdateWorks) {
   const FeatureFlags& features = FeatureFlags::GetInstance();
   EXPECT_TRUE(features.GetFlags().enable_async_bandwidth_upgrade);
-  const_cast<FeatureFlags&>(FeatureFlags::GetInstance())
-      .SetFlags({.enable_async_bandwidth_upgrade = false});
+  FeatureFlags::GetMutableInstanceForTesting().SetFlags(
+      {.enable_async_bandwidth_upgrade = false});
 
   EXPECT_FALSE(features.GetFlags().enable_async_bandwidth_upgrade);
 }

internal/platform/medium_environment.cc

@@ -1147,7 +1147,7 @@ void MediumEnvironment::UnregisterWifiHotspotMedium(
 }
 
 void MediumEnvironment::SetFeatureFlags(const FeatureFlags::Flags& flags) {
-  const_cast<FeatureFlags&>(FeatureFlags::GetInstance()).SetFlags(flags);
+  FeatureFlags::GetMutableInstanceForTesting().SetFlags(flags);
 }
 
 std::optional<FakeClock*> MediumEnvironment::GetSimulatedClock() {