DevTools: [Elements] Implement "Copy CSS Path" context menu item for elements

LayoutTests/inspector/elements/elements-css-path-expected.txt

Index: LayoutTests/inspector/elements/elements-css-path-expected.txt
diff --git a/LayoutTests/inspector/elements/elements-css-path-expected.txt b/LayoutTests/inspector/elements/elements-css-path-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..d8a4eff04abb8059f8e21d37378b3441e4231f4a
--- /dev/null
+++ b/LayoutTests/inspector/elements/elements-css-path-expected.txt
@@ -0,0 +1,55 @@
+Tests DOMNode.cssPath()
+
+ид
+класс
+   html
+    head
+      head > meta
+      #script-id
+      head > script:nth-child(3)
+      #test-script
+    body
+      body > p
+      body > article:nth-child(2)
+      body > article:nth-child(3)
+      #ids
+        #ids > div:nth-child(1)
+        #ids > div:nth-child(2)
+        #inner-id
+        #__proto__
+        #\23 \22 ridiculous\22 \2e id
+        #\27 quoted\2e value\27
+        #\2e foo\2e bar
+        #\2d
+        #-a
+        #\2d 0
+        #\37
+        #ид
+        #ids > p
+      #classes
+        #classes > div.foo.bar
+        #classes > div:nth-child(2)
+        #classes > div.\2e foo
+        #classes > div.\2e foo\2e bar
+        #classes > div.\2d
+        #classes > div.-a
+        #classes > div.\2d 0
+        #classes > div.\37
+        #classes > div.класс
+        #classes > div:nth-child(10)
+        #classes > div.__proto__.foo
+        #classes > span
+        #id-with-class
+      #non-unique-classes
+        #non-unique-classes > span:nth-child(1)
+        #non-unique-classes > span:nth-child(2)
+        #non-unique-classes > span:nth-child(3)
+        #non-unique-classes > span.c1.c2.c3
+        #non-unique-classes > span:nth-child(5)
+        #non-unique-classes > div:nth-child(6)
+        #non-unique-classes > div.c1.c2
+        #non-unique-classes > div.c3.c2
+        #non-unique-classes > div.c3.c4
+        #non-unique-classes > div.c1.c4
+        #non-unique-classes > div:nth-child(11)
+