AudioBufferSourceNode.buffer can only be set once.

LayoutTests/webaudio/dom-exceptions-expected.txt

Index: LayoutTests/webaudio/dom-exceptions-expected.txt
diff --git a/LayoutTests/webaudio/dom-exceptions-expected.txt b/LayoutTests/webaudio/dom-exceptions-expected.txt
index 2745dc772c92d6e2e78fab02e4eeb0825046286b..610e9c0e3e44b268be93d0ea1bb7b75c849b6034 100644
--- a/LayoutTests/webaudio/dom-exceptions-expected.txt
+++ b/LayoutTests/webaudio/dom-exceptions-expected.txt
@@ -1,3 +1,4 @@
+CONSOLE WARNING: Setting AudioBufferSourceNode.buffer more than once is deprecated and will no longer work in M45.
 Tests DOM exception messages
 
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
@@ -71,6 +72,7 @@ PASS node.curve is null
 PASS node.curve = new Float32Array(2) did not throw exception.
 PASS source = context.createBufferSource() did not throw exception.
 PASS source.buffer = buffer did not throw exception.
+PASS source.buffer = context.createBuffer(1, 10, context.sampleRate) did not throw exception.
 PASS source.start(-1) threw exception InvalidAccessError: Failed to execute 'start' on 'AudioBufferSourceNode': Start time must be a finite non-negative number: -1.
 PASS source.start(Infinity) threw exception InvalidAccessError: Failed to execute 'start' on 'AudioBufferSourceNode': Start time must be a finite non-negative number: Infinity.
 PASS source.start(-Infinity) threw exception InvalidAccessError: Failed to execute 'start' on 'AudioBufferSourceNode': Start time must be a finite non-negative number: -Infinity.