fix: Fix case sensitivity for drm content type (#2800)

This fixes the case sensitivity in the `DrmEngine` `willSupport` method. This comparison should be case insensitive, particularly for codec profiles described in hex which may be either lower or upper case. The change normalizes both the stored content types and the method arguments.

Closes #2799

AUTHORS

@@ -18,6 +18,7 @@ Adrián Gómez Llorente <[email protected]>
 Alex Jones <[email protected]>
 Alugha GmbH <*@alugha.com>
 Alvaro Velad Galvan <[email protected]>
+Anthony Stansbridge <[email protected]>
 Bonnier Broadcasting <*@bonnierbroadcasting.com>
 Bryan Huh <[email protected]>
 Esteban Dosztal <[email protected]>

CONTRIBUTORS

@@ -26,6 +26,7 @@ Aaron Vaage <[email protected]>
 Alex Jones <[email protected]>
 Alvaro Velad Galvan <[email protected]>
 Andy Hochhaus <[email protected]>
+Anthony Stansbridge <[email protected]>
 Ashutosh Kumar Mukhiya <[email protected]>
 Benjamin Wallberg <[email protected]>
 Boris Cupac <[email protected]>

lib/media/drm_engine.js

@@ -582,7 +582,7 @@ shaka.media.DrmEngine = class {
       return true;
     }
 
-    return this.supportedTypes_.has(contentType);
+    return this.supportedTypes_.has(contentType.toLowerCase());
   }
 
   /**
@@ -831,11 +831,11 @@ shaka.media.DrmEngine = class {
       const videoCaps = realConfig.videoCapabilities || [];
 
       for (const cap of audioCaps) {
-        this.supportedTypes_.add(cap.contentType);
+        this.supportedTypes_.add(cap.contentType.toLowerCase());
       }
 
       for (const cap of videoCaps) {
-        this.supportedTypes_.add(cap.contentType);
+        this.supportedTypes_.add(cap.contentType.toLowerCase());
       }
 
       goog.asserts.assert(this.supportedTypes_.size,

test/media/drm_engine_unit.js

@@ -260,6 +260,7 @@ describe('DrmEngine', () => {
       expect(drmEngine.initialized()).toBe(true);
       expect(drmEngine.willSupport('audio/webm')).toBeTruthy();
       expect(drmEngine.willSupport('video/mp4; codecs="fake"')).toBeTruthy();
+      expect(drmEngine.willSupport('video/mp4; codecs="FAKE"')).toBeTruthy();
 
       // Because DrmEngine will err on being too accepting, make sure it will
       // reject something. However, we can only check that it is actually