Deprecate case-insensitive matching for |usemap| attribute

third_party/WebKit/Source/core/dom/TreeScope.cpp

Index: third_party/WebKit/Source/core/dom/TreeScope.cpp
diff --git a/third_party/WebKit/Source/core/dom/TreeScope.cpp b/third_party/WebKit/Source/core/dom/TreeScope.cpp
index 422de1a85924481fffd9b307750560cfd402d758..189c39f471c2d6b34d26e11b056d79112e3a7683 100644
--- a/third_party/WebKit/Source/core/dom/TreeScope.cpp
+++ b/third_party/WebKit/Source/core/dom/TreeScope.cpp
@@ -40,11 +40,14 @@
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/DOMSelection.h"
 #include "core/events/EventPath.h"
+#include "core/frame/Deprecation.h"
+#include "core/frame/FrameConsole.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLAnchorElement.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/html/HTMLMapElement.h"
+#include "core/inspector/ConsoleMessage.h"
 #include "core/layout/HitTestResult.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/page/FocusController.h"
@@ -55,6 +58,21 @@ namespace blink {
 
 using namespace HTMLNames;
 
+namespace {
+
+void addSingletonDeprecationMessageForImageMap(const LocalFrame* frame,
+                                               UseCounter::Feature feature,
+                                               const String& usemap,
+                                               const AtomicString& name) {
+  if (!frame)
+    return;
+  frame->console().addSingletonMessage(ConsoleMessage::create(
+      DeprecationMessageSource, WarningMessageLevel,
+      Deprecation::deprecationMessage(feature) + " Comparing usemap=" + usemap +
+          " and name=" + name));
+}
+}
+
 TreeScope::TreeScope(ContainerNode& rootNode, Document& document)
     : m_rootNode(&rootNode),
       m_document(&document),
@@ -186,11 +204,11 @@ HTMLMapElement* TreeScope::getImageMap(const String& url) const {
   size_t hashPos = url.find('#');
   String name = hashPos == kNotFound ? url : url.substring(hashPos + 1);
   HTMLMapElement* map = toHTMLMapElement(
-      rootNode().document().isHTMLDocument()
+      document().isHTMLDocument()
           ? m_imageMapsByName->getElementByLowercasedMapName(
                 AtomicString(name.lower()), this)
           : m_imageMapsByName->getElementByMapName(AtomicString(name), this));
-  if (!map || !rootNode().document().isHTMLDocument())
+  if (!map || !document().isHTMLDocument())
     return map;
   const AtomicString& nameValue = map->fastGetAttribute(nameAttr);
   if (nameValue.isNull())
@@ -198,14 +216,17 @@ HTMLMapElement* TreeScope::getImageMap(const String& url) const {
   String strippedName = nameValue;
   if (strippedName.startsWith('#'))
     strippedName = strippedName.substring(1);
-  if (strippedName == name)
-    UseCounter::count(rootNode().document(), UseCounter::MapNameMatchingStrict);
-  else if (equalIgnoringASCIICase(strippedName, name))
-    UseCounter::count(rootNode().document(),
-                      UseCounter::MapNameMatchingASCIICaseless);
-  else
-    UseCounter::count(rootNode().document(),
-                      UseCounter::MapNameMatchingUnicodeLower);
+  if (strippedName == name) {
+    UseCounter::count(document(), UseCounter::MapNameMatchingStrict);
+  } else if (equalIgnoringASCIICase(strippedName, name)) {
+    addSingletonDeprecationMessageForImageMap(
+        document().frame(), UseCounter::MapNameMatchingASCIICaseless, url,
+        nameValue);
+  } else {
+    addSingletonDeprecationMessageForImageMap(
+        document().frame(), UseCounter::MapNameMatchingUnicodeLower, url,
+        nameValue);
+  }
   return map;
 }