DevTools: allow injecting CSS rules without breaking styles sidebar.

LayoutTests/inspector-protocol/css/cssom-matching-rules-multiple-expected.txt

Index: LayoutTests/inspector-protocol/css/cssom-matching-rules-multiple-expected.txt
diff --git a/LayoutTests/inspector-protocol/css/cssom-matching-rules-multiple-expected.txt b/LayoutTests/inspector-protocol/css/cssom-matching-rules-multiple-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..f93fa34de0325e7b3fe0e3af238561e22411e2dc
--- /dev/null
+++ b/LayoutTests/inspector-protocol/css/cssom-matching-rules-multiple-expected.txt
@@ -0,0 +1,141 @@
+The test verifies CSS.getMatchedStylesForNode when used concurrently with multiple CSSOM modifications.
+
+
+Running test: testModifyRule
+--------------
+Original rule:
+*#test* {    regular
+    color: red;
+}
+*#test* {    regular
+    color: green;
+}
+*#test* {    regular
+    color: blue;
+}
+*#test* {    regular
+    width: 10%;
+}
+*#test* {    regular
+    width: 20%;
+}
+*#test* {    regular
+    width: 30%;
+}
+*#test* {    regular
+    width: 40%;
+}
+*#test* {    regular
+    width: 50%;
+}
+*#test* {    regular
+    width: 60%;
+}
+Mutating 3rd:
+---------------
+*#test* {    regular
+    color: red;
+}
+*#test* {    regular
+    color: green;
+}
+*#test* {    regular
+    color: blue;
+}
+*#test* {    regular    readonly
+    color: red;
+}
+*#test* {    regular
+    width: 20%;
+}
+*#test* {    regular
+    width: 30%;
+}
+*#test* {    regular
+    width: 40%;
+}
+*#test* {    regular
+    width: 50%;
+}
+*#test* {    regular
+    width: 60%;
+}
+Mutating 4th:
+--------------
+*#test* {    regular
+    color: red;
+}
+*#test* {    regular
+    color: green;
+}
+*#test* {    regular
+    color: blue;
+}
+*#test* {    regular    readonly
+    color: red;
+}
+*#test* {    regular    readonly
+    color: green;
+}
+*#test* {    regular
+    width: 30%;
+}
+*#test* {    regular
+    width: 40%;
+}
+*#test* {    regular
+    width: 50%;
+}
+*#test* {    regular
+    width: 60%;
+}
+Mutating 5th:
+--------------
+*#test* {    regular
+    color: red;
+}
+*#test* {    regular
+    color: green;
+}
+*#test* {    regular
+    color: blue;
+}
+*#test* {    regular    readonly
+    color: red;
+}
+*#test* {    regular    readonly
+    color: green;
+}
+*#test* {    regular    readonly
+    color: blue;
+}
+*#test* {    regular
+    width: 40%;
+}
+*#test* {    regular
+    width: 50%;
+}
+*#test* {    regular
+    width: 60%;
+}
+Delete first 3:
+---------------
+*#test* {    regular
+    color: red;
+}
+*#test* {    regular
+    color: green;
+}
+*#test* {    regular
+    color: blue;
+}
+*#test* {    regular
+    width: 40%;
+}
+*#test* {    regular
+    width: 50%;
+}
+*#test* {    regular
+    width: 60%;
+}
+