Let blink scheduler know when background parsing a document

third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp

Index: third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp
diff --git a/third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp b/third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp
index 23d77389115ddb12e8372eb3130f683617a86f38..e40f0f66c43c5c2aedd4898134f5f732799fa5cc 100644
--- a/third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp
+++ b/third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp
@@ -721,6 +721,8 @@ void HTMLDocumentParser::startBackgroundParser()
     ASSERT(document());
     m_haveBackgroundParser = true;
 
+    document()->frame()->frameScheduler()->setDocumentParsedInBackground(true);
+
     // Make sure that a resolver is set up, so that the correct viewport dimensions will be fed to the background parser and preload scanner.
     if (document()->loader())
         document()->ensureStyleResolver();
@@ -761,6 +763,8 @@ void HTMLDocumentParser::stopBackgroundParser()
     ASSERT(m_haveBackgroundParser);
     m_haveBackgroundParser = false;
 
+    document()->frame()->frameScheduler()->setDocumentParsedInBackground(false);
+
     // Make this sync, as lsan triggers on some unittests if the task runner is
     // used. Note that these lifetimes will be much more concrete if
     // ParseHTMLOnMainThread lands (the lookahead parser will be a member).