Add Starboard Feature Experiment

With the Starboard Features Experiment merged, we are now able to
properly implement this experiment feature flag with a starboard
feature.

Bug: 423927047

Author: johnedocampo

cobalt/android/apk/app/src/main/java/dev/cobalt/media/MediaCodecBridge.java

@@ -72,10 +72,6 @@ class MediaCodecBridge {
   private int mFps = 30;
   private final boolean mIsTunnelingPlayback;
 
-  // TODO: (b/423927047) Once the Starboard Extension for Chromium Features
-  // lands, replace this macro with a starboard features.
-  private boolean mBufferFlagDecodeOnlyExperiment = false;
-
   private MediaCodec.OnFrameRenderedListener mFrameRendererListener;
   private MediaCodec.OnFirstTunnelFrameReadyListener mFirstTunnelFrameReadyListener;
 
@@ -402,10 +398,10 @@ public static boolean isFrameRenderedCallbackEnabled() {
     return Build.VERSION.SDK_INT >= 34;
   }
 
-  private boolean isDecodeOnly(long presentationTimeUs) {
+  private boolean isDecodeOnly(long presentationTimeUs, boolean decodeOnlyExperiment) {
     // Starting with Android 14, we can use BUFFER_FLAG_DECODE_ONLY to explicitly skip video frames
     // before the seek time so that they won't be rendered.
-    return Build.VERSION.SDK_INT >= 34 && (mBufferFlagDecodeOnlyExperiment) && (presentationTimeUs < mSeekToTime);
+    return Build.VERSION.SDK_INT >= 34 && decodeOnlyExperiment && (presentationTimeUs < mSeekToTime);
   }
 
   @CalledByNative
@@ -752,10 +748,10 @@ private ByteBuffer getOutputBuffer(int index) {
 
   @CalledByNative
   private int queueInputBuffer(
-      int index, int offset, int size, long presentationTimeUs, int flags) {
+      int index, int offset, int size, long presentationTimeUs, int flags, boolean decodeOnlyExperiment) {
     resetLastPresentationTimeIfNeeded(presentationTimeUs);
     try {
-      if (isDecodeOnly(presentationTimeUs)) {
+      if (isDecodeOnly(presentationTimeUs, decodeOnlyExperiment)) {
         flags |= MediaCodec.BUFFER_FLAG_DECODE_ONLY;
       }
       mMediaCodec.get().queueInputBuffer(index, offset, size, presentationTimeUs, flags);
@@ -778,7 +774,8 @@ private int queueSecureInputBuffer(
       int cipherMode,
       int blocksToEncrypt,
       int blocksToSkip,
-      long presentationTimeUs) {
+      long presentationTimeUs,
+      boolean decodeOnlyExperiment) {
     resetLastPresentationTimeIfNeeded(presentationTimeUs);
     try {
       CryptoInfo cryptoInfo = new CryptoInfo();
@@ -792,10 +789,9 @@ private int queueSecureInputBuffer(
         return MediaCodecStatus.ERROR;
       }
 
-      int flags = 0;
-      if (isDecodeOnly(presentationTimeUs)) {
-        flags |= MediaCodec.BUFFER_FLAG_DECODE_ONLY;
-      }
+      int flags = isDecodeOnly(presentationTimeUs, decodeOnlyExperiment)
+                ? MediaCodec.BUFFER_FLAG_DECODE_ONLY
+                : 0;
       mMediaCodec.get().queueSecureInputBuffer(index, offset, cryptoInfo, presentationTimeUs, flags);
     } catch (MediaCodec.CryptoException e) {
       int errorCode = e.getErrorCode();

starboard/android/shared/media_codec_bridge.cc

@@ -314,15 +314,13 @@ jint MediaCodecBridge::QueueInputBuffer(jint index,
                                         jlong presentation_time_microseconds,
                                         jint flags) {
   JNIEnv* env = AttachCurrentThread();
-  if (starboard::features::FeatureList::IsEnabled(
-          starboard::features::kStarboardBufferFlagDecodeOnlyExperiment)) {
-    SB_LOG(INFO) << "Feature has been enabled";
-  } else {
-    SB_LOG(INFO) << "Feature is not enabled";
-  }
+
+  bool enable_decode_only_experiment =
+      starboard::features::FeatureList::IsEnabled(
+          starboard::features::kStarboardBufferFlagDecodeOnlyExperiment);
   return Java_MediaCodecBridge_queueInputBuffer(
       env, j_media_codec_bridge_, index, offset, size,
-      presentation_time_microseconds, flags);
+      presentation_time_microseconds, flags, enable_decode_only_experiment);
 }
 
 jint MediaCodecBridge::QueueSecureInputBuffer(
@@ -362,10 +360,15 @@ jint MediaCodecBridge::QueueSecureInputBuffer(
     blocks_to_skip = drm_sample_info.encryption_pattern.skip_byte_block;
   }
 
+  jboolean enable_decode_only_experiment =
+      starboard::features::FeatureList::IsEnabled(
+          features::kStarboardBufferFlagDecodeOnlyExperiment);
+
   return Java_MediaCodecBridge_queueSecureInputBuffer(
       env, j_media_codec_bridge_, index, offset, j_iv, j_key_id, j_clear_bytes,
       j_encrypted_bytes, subsample_count, cipher_mode, blocks_to_encrypt,
-      blocks_to_skip, presentation_time_microseconds);
+      blocks_to_skip, presentation_time_microseconds,
+      enable_decode_only_experiment);
 }
 
 ScopedJavaLocalRef<jobject> MediaCodecBridge::GetOutputBuffer(jint index) {