Update pseudo-element tag names to follow standard (::before etc).

Currently this only effects devTools logs.
This change is intended to be used by an upcoming patch to the animations
code, where KeyframeEffect will use PseudoElementTagName.

Bug: 981894
Change-Id: Iddde38c575a1769bf00f53c82a056bf1a029c6d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1928307Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Mason Freed <masonfreed@chromium.org>
Reviewed-by: Kevin Ellis <kevers@chromium.org>
Commit-Queue: George Steel <gtsteel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#720274}

third_party/blink/renderer/core/dom/pseudo_element.cc

@@ -45,6 +45,8 @@ namespace blink {
 PseudoElement* PseudoElement::Create(Element* parent, PseudoId pseudo_id) {
   if (pseudo_id == kPseudoIdFirstLetter)
     return MakeGarbageCollected<FirstLetterPseudoElement>(parent);
+  DCHECK(pseudo_id == kPseudoIdAfter || pseudo_id == kPseudoIdBefore ||
+         pseudo_id == kPseudoIdBackdrop || pseudo_id == kPseudoIdMarker);
   return MakeGarbageCollected<PseudoElement>(parent, pseudo_id);
 }
 
@@ -52,51 +54,43 @@ const QualifiedName& PseudoElementTagName(PseudoId pseudo_id) {
   switch (pseudo_id) {
     case kPseudoIdAfter: {
       DEFINE_STATIC_LOCAL(QualifiedName, after,
-                          (g_null_atom, "<pseudo:after>", g_null_atom));
+                          (g_null_atom, "::after", g_null_atom));
       return after;
     }
     case kPseudoIdBefore: {
       DEFINE_STATIC_LOCAL(QualifiedName, before,
-                          (g_null_atom, "<pseudo:before>", g_null_atom));
+                          (g_null_atom, "::before", g_null_atom));
       return before;
     }
     case kPseudoIdBackdrop: {
       DEFINE_STATIC_LOCAL(QualifiedName, backdrop,
-                          (g_null_atom, "<pseudo:backdrop>", g_null_atom));
+                          (g_null_atom, "::backdrop", g_null_atom));
       return backdrop;
     }
     case kPseudoIdFirstLetter: {
       DEFINE_STATIC_LOCAL(QualifiedName, first_letter,
-                          (g_null_atom, "<pseudo:first-letter>", g_null_atom));
+                          (g_null_atom, "::first-letter", g_null_atom));
       return first_letter;
     }
     case kPseudoIdMarker: {
       DEFINE_STATIC_LOCAL(QualifiedName, marker,
-                          (g_null_atom, "<pseudo:marker>", g_null_atom));
+                          (g_null_atom, "::marker", g_null_atom));
       return marker;
     }
     default:
       NOTREACHED();
   }
   DEFINE_STATIC_LOCAL(QualifiedName, name,
-                      (g_null_atom, "<pseudo>", g_null_atom));
+                      (g_null_atom, "::unknown", g_null_atom));
   return name;
 }
 
-String PseudoElement::PseudoElementNameForEvents(PseudoId pseudo_id) {
-  DEFINE_STATIC_LOCAL(const String, after, ("::after"));
-  DEFINE_STATIC_LOCAL(const String, before, ("::before"));
-  DEFINE_STATIC_LOCAL(const String, marker, ("::marker"));
-  switch (pseudo_id) {
-    case kPseudoIdAfter:
-      return after;
-    case kPseudoIdBefore:
-      return before;
-    case kPseudoIdMarker:
-      return marker;
-    default:
-      return g_empty_string;
-  }
+const AtomicString& PseudoElement::PseudoElementNameForEvents(
+    PseudoId pseudo_id) {
+  if (pseudo_id == kPseudoIdNone)
+    return g_null_atom;
+  else
+    return PseudoElementTagName(pseudo_id).LocalName();
 }
 
 PseudoElement::PseudoElement(Element* parent, PseudoId pseudo_id)

third_party/blink/renderer/core/dom/pseudo_element.h

@@ -51,7 +51,7 @@ class CORE_EXPORT PseudoElement : public Element {
   scoped_refptr<ComputedStyle> LayoutStyleForDisplayContents(
       const ComputedStyle&);
 
-  static String PseudoElementNameForEvents(PseudoId);
+  static const AtomicString& PseudoElementNameForEvents(PseudoId);
 
   // Pseudo element are not allowed to be the inner node for hit testing. Find
   // the closest ancestor which is a real dom node.
@@ -75,7 +75,7 @@ class CORE_EXPORT PseudoElement : public Element {
   PseudoId pseudo_id_;
 };
 
-const QualifiedName& PseudoElementTagName();
+const QualifiedName& PseudoElementTagName(PseudoId);
 
 bool PseudoElementLayoutObjectIsNeeded(const ComputedStyle*);
 

third_party/blink/web_tests/inspector-protocol/dom-snapshot/dom-snapshot-captureSnapshot-pseudo-element-expected.txt

@@ -662,7 +662,7 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
         [17] : P
         [18] : class
         [19] : c1
-        [20] : <pseudo:first-letter>
+        [20] : ::first-letter
         [21] : 100
         [22] : rgb(0, 128, 0)
         [23] : I
@@ -676,7 +676,7 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
         [31] : 700
         [32] : rgb(0, 0, 255)
         [33] : s
-        [34] : <pseudo:before>
+        [34] : ::before
         [35] : quare: 
         [36] : 1
         [37] : ! 

third_party/blink/web_tests/inspector-protocol/dom-snapshot/dom-snapshot-getSnapshot-pseudo-element-expected.txt

@@ -123,7 +123,7 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
     },
     {
       "nodeType": 1,
-      "nodeName": "<pseudo:first-letter>",
+      "nodeName": "::first-letter",
       "nodeValue": "",
       "backendNodeId": "<number>",
       "layoutNodeIndex": 5,
@@ -163,7 +163,7 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
     },
     {
       "nodeType": 1,
-      "nodeName": "<pseudo:first-letter>",
+      "nodeName": "::first-letter",
       "nodeValue": "",
       "backendNodeId": "<number>",
       "layoutNodeIndex": 9,
@@ -214,7 +214,7 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
     },
     {
       "nodeType": 1,
-      "nodeName": "<pseudo:first-letter>",
+      "nodeName": "::first-letter",
       "nodeValue": "",
       "backendNodeId": "<number>",
       "layoutNodeIndex": 14,
@@ -222,7 +222,7 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
     },
     {
       "nodeType": 1,
-      "nodeName": "<pseudo:before>",
+      "nodeName": "::before",
       "nodeValue": "",
       "backendNodeId": "<number>",
       "layoutNodeIndex": 19,

third_party/blink/web_tests/platform/win/paint/invalidation/box/hover-pseudo-borders-expected.txt

@@ -7,7 +7,7 @@
       "backgroundColor": "#FFFFFF",
       "paintInvalidations": [
         {
-          "object": "NGPhysicalBoxFragment LayoutNGBlockFlow (positioned) \u003Cpseudo:after\u003E",
+          "object": "NGPhysicalBoxFragment LayoutNGBlockFlow (positioned) ::after",
           "rect": [138, 8, 100, 100],
           "reason": "style change"
         },