Bug 1711912 - Set flag on clear key CDM if created using special protection query key system. r=alwu

This lets the clear key CDM behave differently if it's created with the
protection query key system. The different behaviour will be implemented in
following patches and gated behind the member set here.

Differential Revision: https://phabricator.services.mozilla.com/D122632

media/gmp-clearkey/0.1/ClearKeyCDM.cpp

@@ -160,3 +160,9 @@ void ClearKeyCDM::Destroy() {
 #endif
   delete this;
 }
+
+void ClearKeyCDM::EnableProtectionQuery() {
+  MOZ_ASSERT(!mIsProtectionQueryEnabled,
+             "Should not be called more than once per CDM");
+  mIsProtectionQueryEnabled = true;
+}

media/gmp-clearkey/0.1/ClearKeyCDM.h

@@ -25,6 +25,7 @@ class ClearKeyCDM : public cdm::ContentDecryptionModule_10 {
 #ifdef ENABLE_WMF
   RefPtr<VideoDecoder> mVideoDecoder;
 #endif
+  bool mIsProtectionQueryEnabled = false;
 
  protected:
   cdm::Host_10* mHost;
@@ -94,6 +95,8 @@ class ClearKeyCDM : public cdm::ContentDecryptionModule_10 {
                    uint32_t aStorageIdSize) override;
 
   void Destroy() override;
+
+  void EnableProtectionQuery();
 };
 
 #endif

media/gmp-clearkey/0.1/gmp-clearkey.cpp

@@ -22,6 +22,7 @@
 
 #include "ClearKeyCDM.h"
 #include "ClearKeySessionManager.h"
+#include "mozilla/dom/KeySystemNames.h"
 // This include is required in order for content_decryption_module to work
 // on Unix systems.
 #include "stddef.h"
@@ -84,6 +85,12 @@ void* CreateCdmInstance(int cdm_interface_version, const char* key_system,
 
   CK_LOGE("Created ClearKeyCDM instance!");
 
+  if (strncmp(key_system, mozilla::kClearKeyWithProtectionQueryKeySystemName,
+              key_system_size) == 0) {
+    CK_LOGE("Enabling protection query on ClearKeyCDM instance!");
+    clearKey->EnableProtectionQuery();
+  }
+
   return clearKey;
 }