Bug 1546506 - Add an assertion to ensure that we won't construct SeekTarget with invalid time. r=bryce

We should only use valid time to construct a `SeekTarget`, because we can't get the value from the invalid time.

This can help us to prevent having a crash when request data value from an invalid time.

Differential Revision: https://phabricator.services.mozilla.com/D28564

--HG--
extra : moz-landing-system : lando

dom/media/SeekTarget.h

@@ -28,11 +28,15 @@ struct SeekTarget {
         mType(SeekTarget::Invalid),
         mVideoOnly(false) {}
   SeekTarget(const media::TimeUnit& aTime, Type aType, bool aVideoOnly = false)
-      : mTime(aTime), mType(aType), mVideoOnly(aVideoOnly) {}
+      : mTime(aTime), mType(aType), mVideoOnly(aVideoOnly) {
+    MOZ_ASSERT(mTime.IsValid());
+  }
   SeekTarget(const SeekTarget& aOther)
       : mTime(aOther.mTime),
         mType(aOther.mType),
-        mVideoOnly(aOther.mVideoOnly) {}
+        mVideoOnly(aOther.mVideoOnly) {
+    MOZ_ASSERT(mTime.IsValid());
+  }
   bool IsValid() const { return mType != SeekTarget::Invalid; }
   void Reset() {
     mTime = media::TimeUnit::Invalid();
@@ -40,11 +44,11 @@ struct SeekTarget {
     mVideoOnly = false;
   }
   media::TimeUnit GetTime() const {
-    NS_ASSERTION(mTime.IsValid(), "Invalid SeekTarget");
+    MOZ_ASSERT(mTime.IsValid(), "Invalid SeekTarget");
     return mTime;
   }
   void SetTime(const media::TimeUnit& aTime) {
-    NS_ASSERTION(aTime.IsValid(), "Invalid SeekTarget destination");
+    MOZ_ASSERT(aTime.IsValid(), "Invalid SeekTarget destination");
     mTime = aTime;
   }
   void SetType(Type aType) { mType = aType; }