Automated g4 rollback of changelist 279825051.

*** Reason for rollback ***

Causes a compilation error on desktop integration tests.

*** Original change description ***

Removed mutex usage in Admob destructor to signal the completion of Destroy. The use of Mutex in this case was not thread-safe. Replaced the mutex with semaphores and added an integration test for iOS and Android.

***

PiperOrigin-RevId: 280033445

Author: Googler

admob/src/android/banner_view_internal_android.cc

@@ -14,8 +14,6 @@
  * limitations under the License.
  */
 
-#include "admob/src/android/banner_view_internal_android.h"
-
 #include <assert.h>
 #include <jni.h>
 
@@ -25,13 +23,13 @@
 #include "admob/admob_resources.h"
 #include "admob/src/android/ad_request_converter.h"
 #include "admob/src/android/admob_android.h"
+#include "admob/src/android/banner_view_internal_android.h"
 #include "admob/src/common/admob_common.h"
 #include "admob/src/include/firebase/admob.h"
 #include "admob/src/include/firebase/admob/banner_view.h"
 #include "admob/src/include/firebase/admob/types.h"
 #include "app/src/assert.h"
 #include "app/src/mutex.h"
-#include "app/src/semaphore.h"
 #include "app/src/util_android.h"
 
 namespace firebase {
@@ -61,13 +59,21 @@ BannerViewInternalAndroid::BannerViewInternalAndroid(BannerView* base)
 BannerViewInternalAndroid::~BannerViewInternalAndroid() {
   JNIEnv* env = ::firebase::admob::GetJNI();
 
-  DestroyInternalData();
-
-  Semaphore semaphore(0);
-  InvokeNullary(kBannerViewFnDestroyOnDelete, banner_view_helper::kDestroy)
-      .OnCompletion([&semaphore](const Future<void>&) { semaphore.Post(); });
-  semaphore.Wait();
-
+  // Destroy the banner view so all pending futures / callbacks complete.
+  {
+    Mutex mutex(Mutex::kModeNonRecursive);
+    mutex.Acquire();
+    Destroy().OnCompletion(
+        [](const Future<void>&, void* mutex) {
+          reinterpret_cast<Mutex*>(mutex)->Release();
+        },
+        &mutex);
+    // Acquire a second Mutex lock to block until the Future for the last call
+    // to Destroy() completes at which point the lambda function in OnCompletion
+    // is called and the Mutex lock is released.
+    mutex.Acquire();
+    mutex.Release();
+  }
   env->DeleteGlobalRef(helper_);
   helper_ = nullptr;
 }
@@ -125,7 +131,8 @@ Future<void> BannerViewInternalAndroid::Resume() {
 }
 
 Future<void> BannerViewInternalAndroid::Destroy() {
-  DestroyInternalData();
+  // The bounding box is zeroed on destroy.
+  bounding_box_ = {};
   return InvokeNullary(kBannerViewFnDestroy, banner_view_helper::kDestroy);
 }
 
@@ -207,12 +214,6 @@ Future<void> BannerViewInternalAndroid::InvokeNullary(
   return GetLastResult(fn);
 }
 
-void BannerViewInternalAndroid::DestroyInternalData() {
-  // The bounding box is zeroed on destroy.
-  bounding_box_ = {};
-}
-
-
 }  // namespace internal
 }  // namespace admob
 }  // namespace firebase

admob/src/android/banner_view_internal_android.h

@@ -78,9 +78,6 @@ class BannerViewInternalAndroid : public BannerViewInternal {
   // the future callback pointer.
   Future<void> InvokeNullary(BannerViewFn fn,
                              banner_view_helper::Method method);
-
-  // Cleans up any C++ side data before invoking the Android SDK to do the same.
-  void DestroyInternalData();
 };
 
 }  // namespace internal

admob/src/common/banner_view_internal.h

@@ -35,7 +35,6 @@ enum BannerViewFn {
   kBannerViewFnPause,
   kBannerViewFnResume,
   kBannerViewFnDestroy,
-  kBannerViewFnDestroyOnDelete,
   kBannerViewFnMoveTo,
   kBannerViewFnCount
 };