Fix NOTREACHED() in abortIfUpdating() when aborting 0-byte appendBuffer

third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp

Index: third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
diff --git a/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp b/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
index 58c74056c0aa95cff1584e1451963747d47ff7f4..1e3286b94922987c3fcb4f253a1d4816d78683e2 100644
--- a/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
+++ b/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
@@ -482,12 +482,10 @@ void SourceBuffer::abortIfUpdating()
     DCHECK_EQ(m_pendingRemoveStart, -1);
 
     const char* traceEventName = 0;
-    if (!m_pendingAppendData.isEmpty()) {

[wolenetz, 2016/09/02 20:10:53]

It's entirely possible for pendingAppendData to be empty when aborting an
asynchronous 0-byte appendBuffer. This CL avoids the NOTREACHED() on debug
builds, and uses the correct traceEventName in all build types.

-        traceEventName = "SourceBuffer::appendBuffer";
-    } else if (m_stream) {
+    if (m_stream) {
         traceEventName = "SourceBuffer::appendStream";
     } else {
-        NOTREACHED();
+        traceEventName = "SourceBuffer::appendBuffer";
     }
 
     // 4.1. Abort the buffer append and stream append loop algorithms if they are running.