Convert first letter into a pseudo element.

Source/core/inspector/InspectorCSSAgent.cpp

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 771 matching lines @@
         for (Node* child = node->firstChild(); child; child = child->nextSibling()) {
             if (child->nodeType() == Node::TEXT_NODE && child->renderer())
                 textNodes.append(toText(child));
         }
     }
 
     HashCountedSet<String> fontStats;
     for (size_t i = 0; i < textNodes.size(); ++i) {
         RenderText* renderer = textNodes[i]->renderer();
         collectPlatformFontsForRenderer(renderer, &fontStats);
-        if (renderer->isTextFragment()) {
-            RenderTextFragment* textFragment = toRenderTextFragment(renderer);
-            if (textFragment->firstLetter()) {
-                RenderBoxModelObject* firstLetter = textFragment->firstLetter();
-                for (RenderObject* current = firstLetter->slowFirstChild(); current; current = current->nextSibling()) {
-                    if (current->isText())
-                        collectPlatformFontsForRenderer(toRenderText(current), &fontStats);
-                }
-            }
-        }
+
+        if (!renderer->isTextFragment())
+            continue;
+
+        // If we're the remaining text from a first-letter then our previous
+        // sibling has to be the first-letter renderer.
+        RenderObject* previous = renderer->previousSibling();
+        if (!previous)
+            continue;
+
+        if (!previous->isPseudoElement() || !previous->node()->isFirstLetterPseudoElement())
+            continue;
+
+        // The first-letter pseudoElement only has one child, which is the
+        // first-letter renderer.
+        RenderObject* firstLetterRenderer = previous->slowFirstChild();
+        ASSERT(firstLetterRenderer && firstLetterRenderer->isText());

[Julien - ping for review, 2014/10/09 18:24:48]

toRenderText will also check for isText but in release too so this checks seems
redundant.

Also when you have some logical ors in ASSERT, it's a sign that it should be
split up in several ASSERTs.

[dsinclair, 2014/10/09 21:14:22]

Done (removed the assert).

So, in general, is:

ASSERT(firstLetterRenderer)
ASSERT(firstLetterRenderer->isText())

preferable to the &&'d version?

[Julien - ping for review, 2014/10/10 14:47:07]

From my perspective yes because if ASSERT(firstLetterRenderer &&
firstLetterRenderer->isText()) fails you don't know which clause caused it and
have to run through a debugger to know.

[dsinclair, 2014/10/10 18:06:53]

Acknowledged.

+        collectPlatformFontsForRenderer(toRenderText(firstLetterRenderer), &fontStats);
     }
 
     platformFonts = TypeBuilder::Array<TypeBuilder::CSS::PlatformFontUsage>::create();
     for (HashCountedSet<String>::iterator it = fontStats.begin(), end = fontStats.end(); it != end; ++it) {
         RefPtr<TypeBuilder::CSS::PlatformFontUsage> platformFont = TypeBuilder::CSS::PlatformFontUsage::create()
             .setFamilyName(it->key)
             .setGlyphCount(it->value);
         platformFonts->addItem(platformFont);
     }
 }
@@ skipping 660 matching lines @@
     visitor->trace(m_invalidatedDocuments);
     visitor->trace(m_nodeToInspectorStyleSheet);
     visitor->trace(m_documentToViaInspectorStyleSheet);
 #endif
     visitor->trace(m_inspectorUserAgentStyleSheet);
     InspectorBaseAgent::trace(visitor);
 }
 
 } // namespace blink