Bug 1585805 [wpt PR 19478] - Update wpt metadata, a=testonly

wpt-pr: 19478
wpt-type: metadata

testing/web-platform/meta/encoding/streams/backpressure.any.js.ini

@@ -2,21 +2,68 @@
   [backpressure]
     expected: FAIL
 
+  [write() should not complete until read relieves backpressure for TextEncoderStream]
+    expected: FAIL
+
+  [additional writes should wait for backpressure to be relieved for class TextDecoderStream]
+    expected: FAIL
+
+  [write() should not complete until read relieves backpressure for TextDecoderStream]
+    expected: FAIL
+
+  [additional writes should wait for backpressure to be relieved for class TextEncoderStream]
+    expected: FAIL
+
 
 [backpressure.https.any.serviceworker.html]
   expected: TIMEOUT
 
 [backpressure.any.worker.html]
   expected:
-    if processor == "aarch64": ["OK", "CRASH"]
+    if processor == "aarch64": [OK, CRASH]
   [backpressure]
     expected: FAIL
 
+  [write() should not complete until read relieves backpressure for TextEncoderStream]
+    expected: FAIL
+
+  [additional writes should wait for backpressure to be relieved for class TextDecoderStream]
+    expected: FAIL
+
+  [write() should not complete until read relieves backpressure for TextDecoderStream]
+    expected: FAIL
+
+  [additional writes should wait for backpressure to be relieved for class TextEncoderStream]
+    expected: FAIL
+
 
 [backpressure.any.sharedworker.html]
-  expected: TIMEOUT
+  [write() should not complete until read relieves backpressure for TextEncoderStream]
+    expected: FAIL
+
+  [additional writes should wait for backpressure to be relieved for class TextDecoderStream]
+    expected: FAIL
+
+  [write() should not complete until read relieves backpressure for TextDecoderStream]
+    expected: FAIL
+
+  [additional writes should wait for backpressure to be relieved for class TextEncoderStream]
+    expected: FAIL
+
 
 [backpressure.any.serviceworker.html]
   [backpressure]
     expected: FAIL
 
+  [write() should not complete until read relieves backpressure for TextEncoderStream]
+    expected: FAIL
+
+  [additional writes should wait for backpressure to be relieved for class TextDecoderStream]
+    expected: FAIL
+
+  [write() should not complete until read relieves backpressure for TextDecoderStream]
+    expected: FAIL
+
+  [additional writes should wait for backpressure to be relieved for class TextEncoderStream]
+    expected: FAIL
+