Merge "Exclude the default CDM from metrics history." into udc-dev am: 2e84e8b5f7

Original change: https://googleplex-android-review.googlesource.com/c/platform/vendor/widevine/+/22957292

Change-Id: Id2d7277082d1c95195476ac7e23b0c1982f60100
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

libwvdrmengine/cdm/include/cdm_identifier.h

@@ -47,7 +47,7 @@ struct CdmIdentifier {
   // to the default cdm. E.g. no spoid, origin or app package name. Use this
   // comparison in lieu of the == operator when checking to see if the
   // identifier would cause the default provisioned certificate to be used.
-  bool IsEquivalentToDefault() {
+  bool IsEquivalentToDefault() const {
     return spoid == EMPTY_SPOID && origin == EMPTY_ORIGIN &&
            app_package_name == EMPTY_APP_PACKAGE_NAME;
   }

libwvdrmengine/cdm/src/wv_content_decryption_module.cpp

@@ -565,6 +565,10 @@ CdmResponseType WvContentDecryptionModule::GetCurrentMetricsInternal(
 void WvContentDecryptionModule::SaveMetrics(
     const CdmIdentifier& identifier, drm_metrics::WvCdmMetrics&& metrics) {
   if (saved_metrics_snapshots_ == nullptr) return;
+  // The DRM plugin opens and closes many CDMs using the default
+  // identifier.  These metrics are not needed when checking the
+  // metric history.
+  if (identifier.IsEquivalentToDefault()) return;
   saved_metrics_snapshots_->PushMetrics(
       WvMetricsSnapshot::MakeSnapshot(identifier, std::move(metrics)));
 }