Bug 1713116 - Replace "mediakeys-request" literal with MediaKeys::kMediaKeysRequestTopic in C++ code. r=alwu

Differential Revision: https://phabricator.services.mozilla.com/D116106

dom/media/eme/MediaKeySystemAccess.cpp

@@ -1161,7 +1161,8 @@ void MediaKeySystemAccess::NotifyObservers(nsPIDOMWindowInner* aWindow,
           NS_ConvertUTF16toUTF8(json).get());
   nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
   if (obs) {
-    obs->NotifyObservers(aWindow, "mediakeys-request", json.get());
+    obs->NotifyObservers(aWindow, MediaKeys::kMediaKeysRequestTopic,
+                         json.get());
   }
 }
 

dom/media/eme/MediaKeys.cpp

@@ -767,7 +767,6 @@ void MediaKeys::CheckIsElementCapturePossible() {
     jw.End();
   }
 
-  constexpr const char* kMediaKeysRequestTopic = "mediakeys-request";
   MOZ_DIAGNOSTIC_ASSERT(!mCaptureCheckRequestJson.IsEmpty());
   observerService->NotifyObservers(mParent.get(), kMediaKeysRequestTopic,
                                    mCaptureCheckRequestJson.get());

dom/media/eme/MediaKeys.h

@@ -165,6 +165,10 @@ class MediaKeys final : public nsIObserver,
     promise->MaybeResolve(aResult);
   }
 
+  // The topic used for requests related to mediakeys -- observe this to be
+  // notified of such requests.
+  constexpr static const char* kMediaKeysRequestTopic = "mediakeys-request";
+
  private:
   // Instantiate CDMProxy instance.
   // It could be MediaDrmCDMProxy (Widevine on Fennec) or ChromiumCDMProxy (the

dom/media/gmp/GMPServiceParent.cpp

@@ -41,6 +41,10 @@
 #include "prio.h"
 #include "runnable_utils.h"
 
+#ifdef DEBUG
+#  include "mozilla/dom/MediaKeys.h"  // MediaKeys::kMediaKeysRequestTopic
+#endif
+
 using mozilla::ipc::Transport;
 
 namespace mozilla::gmp {
@@ -103,8 +107,8 @@ nsresult GeckoMediaPluginServiceParent::Init() {
       obsService->AddObserver(this, NS_XPCOM_WILL_SHUTDOWN_OBSERVER_ID, false));
 
 #ifdef DEBUG
-  MOZ_ALWAYS_SUCCEEDS(
-      obsService->AddObserver(this, "mediakeys-request", false));
+  MOZ_ALWAYS_SUCCEEDS(obsService->AddObserver(
+      this, dom::MediaKeys::kMediaKeysRequestTopic, false));
 #endif
 
   nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);