DevTools: Support asynchronous call stacks on backend.

LayoutTests/http/tests/inspector/inspector-test.js

Index: LayoutTests/http/tests/inspector/inspector-test.js
diff --git a/LayoutTests/http/tests/inspector/inspector-test.js b/LayoutTests/http/tests/inspector/inspector-test.js
index 35e948c72a732f096bc926b65e8a35e014003cb0..4e42a201c75dc8b832433a18381c7c2f5d350d44 100644
--- a/LayoutTests/http/tests/inspector/inspector-test.js
+++ b/LayoutTests/http/tests/inspector/inspector-test.js
@@ -94,6 +94,10 @@ InspectorTest.check = function(passCondition, failureText)
 
 InspectorTest.addResult = function(text)
 {
+    if (InspectorTest._resultBufferring) {
+        InspectorTest._resultBufferringContent += text + "\n";
+        return;
+    }
     results.push(text);
     if (resultsSynchronized)
         InspectorTest.Output.addResult(text);
@@ -105,6 +109,20 @@ InspectorTest.addResult = function(text)
     }
 }
 
+InspectorTest.beginResultBufferring = function()
+{
+    InspectorTest._resultBufferring = true;
+    InspectorTest._resultBufferringContent = "";
+}
+
+InspectorTest.endResultBufferring = function()
+{
+    var result = InspectorTest._resultBufferringContent || "";
+    delete InspectorTest._resultBufferring;
+    delete InspectorTest._resultBufferringContent;
+    return result;
+}
+
 InspectorTest.addResults = function(textArray)
 {
     if (!textArray)