[Offline Pages] Adding missing image/CSS detection in FrameSerializer.

third_party/WebKit/Source/web/WebFrameSerializer.cpp

Index: third_party/WebKit/Source/web/WebFrameSerializer.cpp
diff --git a/third_party/WebKit/Source/web/WebFrameSerializer.cpp b/third_party/WebKit/Source/web/WebFrameSerializer.cpp
index 5ae9b75c24659cbfe022424e8fb66b0041688498..80fc5f02090a68fe2533da541cfdf22f3456ba87 100644
--- a/third_party/WebKit/Source/web/WebFrameSerializer.cpp
+++ b/third_party/WebKit/Source/web/WebFrameSerializer.cpp
@@ -61,6 +61,7 @@
 #include "platform/wtf/HashMap.h"
 #include "platform/wtf/HashSet.h"
 #include "platform/wtf/Noncopyable.h"
+#include "platform/wtf/PtrUtil.h"
 #include "platform/wtf/Vector.h"
 #include "platform/wtf/text/StringConcatenate.h"
 #include "public/platform/WebString.h"
@@ -95,6 +96,7 @@ class MHTMLFrameSerializerDelegate final : public FrameSerializer::Delegate {
   bool ShouldSkipResource(
       FrameSerializer::ResourceHasCacheControlNoStoreHeader) override;
   Vector<Attribute> GetCustomAttributes(const Element&) override;
+  bool ShouldCollectProblemMetric() override;
 
  private:
   bool ShouldIgnoreHiddenElement(const Element&);
@@ -280,6 +282,10 @@ Vector<Attribute> MHTMLFrameSerializerDelegate::GetCustomAttributes(
   return attributes;
 }
 
+bool MHTMLFrameSerializerDelegate::ShouldCollectProblemMetric() {
+  return web_delegate_.UsePageProblemDetectors();
+}
+
 void MHTMLFrameSerializerDelegate::GetCustomAttributesForImageElement(
     const HTMLImageElement& element,
     Vector<Attribute>* attributes) {