DevTools: Support asynchronous call stacks on backend.

LayoutTests/inspector/debugger/async-callstack-expected.txt

Index: LayoutTests/inspector/debugger/async-callstack-expected.txt
diff --git a/LayoutTests/inspector/debugger/async-callstack-expected.txt b/LayoutTests/inspector/debugger/async-callstack-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..38288a70a770ccd5821c027befb4a9557ef80df7
--- /dev/null
+++ b/LayoutTests/inspector/debugger/async-callstack-expected.txt
@@ -0,0 +1,62 @@
+Tests asynchronous call stacks in debugger.
+
+Debugger was enabled.
+Set timer for test function.
+Captured call stacks in no particular order:
+Call stack:
+    0) animFrame1 (async-callstack.html:30)
+    [Async Call]
+        0) timeout1 (async-callstack.html:19)
+        1) innerTestFunction (async-callstack.html:11)
+    [Async Call]
+        0) testFunction (async-callstack.html:13)
+
+Call stack:
+    0) animFrame2 (async-callstack.html:47)
+    [Async Call]
+        0) animFrame1 (async-callstack.html:32)
+    [Async Call]
+        0) timeout1 (async-callstack.html:19)
+        1) innerTestFunction (async-callstack.html:11)
+    [Async Call]
+        0) testFunction (async-callstack.html:13)
+
+Call stack:
+    0) interval1 (async-callstack.html:37)
+    1) innerInterval1 (async-callstack.html:24)
+    [Async Call]
+        0) timeout1 (async-callstack.html:20)
+        1) innerTestFunction (async-callstack.html:11)
+    [Async Call]
+        0) testFunction (async-callstack.html:13)
+
+Call stack:
+    0) timeout1 (async-callstack.html:18)
+    1) innerTestFunction (async-callstack.html:11)
+    [Async Call]
+        0) testFunction (async-callstack.html:13)
+
+Call stack:
+    0) timeout2 (async-callstack.html:42)
+    [Async Call]
+        0) animFrame1 (async-callstack.html:31)
+    [Async Call]
+        0) timeout1 (async-callstack.html:19)
+        1) innerTestFunction (async-callstack.html:11)
+    [Async Call]
+        0) testFunction (async-callstack.html:13)
+
+Call stack:
+    0) timeout3 (async-callstack.html:61)
+    1) longTail0 (async-callstack.html:50)
+    [Async Call]
+        0) longTail1 (:1)
+    [Async Call]
+        0) longTail2 (:2)
+    [Async Call]
+        0) longTail3 (:3)
+    [Async Call]
+        0) longTail4 (:4)
+
+Debugger was disabled.
+