Provide a method to remove inserted style sheet

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 118 matching lines @@
       Master()->GetStyleEngine().UpdateActiveStyle();
   }
 
   if (tree_scope == document_)
     return GetDocumentStyleSheetCollection().StyleSheetsForStyleSheetList();
 
   return EnsureStyleSheetCollectionFor(tree_scope)
       ->StyleSheetsForStyleSheetList();
 }
 
-void StyleEngine::InjectAuthorSheet(StyleSheetContents* author_sheet) {
-  injected_author_style_sheets_.push_back(TraceWrapperMember<CSSStyleSheet>(
-      this, CSSStyleSheet::Create(author_sheet, *document_)));
+unsigned StyleEngine::InjectAuthorSheet(StyleSheetContents* author_sheet) {
+  injected_author_style_sheets_.push_back(std::make_pair(
+      ++injected_author_sheets_id_count_,
+      TraceWrapperMember<CSSStyleSheet>(
+          this, CSSStyleSheet::Create(author_sheet, *document_))));
+
   MarkDocumentDirty();
+  return injected_author_sheets_id_count_;
+}
+
+void StyleEngine::RemoveInjectedAuthorSheet(unsigned author_sheet_id) {
+  for (size_t i = 0; i < injected_author_style_sheets_.size(); ++i) {
+    if (injected_author_style_sheets_[i].first == author_sheet_id) {
+      injected_author_style_sheets_.erase(i);
+      MarkDocumentDirty();
+    }
+  }
 }
 
 CSSStyleSheet& StyleEngine::EnsureInspectorStyleSheet() {
   if (inspector_style_sheet_)
     return *inspector_style_sheet_;
 
   StyleSheetContents* contents =
       StyleSheetContents::Create(CSSParserContext::Create(*document_));
   inspector_style_sheet_ = CSSStyleSheet::Create(contents, *document_);
   MarkDocumentDirty();
@@ skipping 1015 matching lines @@
   visitor->Trace(media_query_evaluator_);
   visitor->Trace(style_invalidator_);
   visitor->Trace(font_selector_);
   visitor->Trace(text_to_sheet_cache_);
   visitor->Trace(sheet_to_text_cache_);
   visitor->Trace(tracker_);
   CSSFontSelectorClient::Trace(visitor);
 }
 
 DEFINE_TRACE_WRAPPERS(StyleEngine) {
-  for (auto sheet : injected_author_style_sheets_) {
-    visitor->TraceWrappers(sheet);
+  for (const auto& sheet : injected_author_style_sheets_) {
+    visitor->TraceWrappers(sheet.second);
   }
   visitor->TraceWrappers(document_style_sheet_collection_);
 }
 
 }  // namespace blink