Do not send pings for anchor elements in MHTML pages

third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp b/third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp
index b9c7b1b58823f7e66e472f461885c38cae188e73..98fccec2751a80bed96aec0c7e0179396e01e8b5 100644
--- a/third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp
@@ -37,6 +37,7 @@
 #include "core/loader/PingLoader.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/Page.h"
+#include "platform/loader/fetch/ResourceFetcher.h"
 #include "platform/network/NetworkHints.h"
 #include "platform/weborigin/SecurityPolicy.h"
 
@@ -305,6 +306,10 @@ void HTMLAnchorElement::SendPings(const KURL& destination_url) const {
       !GetDocument().GetSettings()->GetHyperlinkAuditingEnabled())
     return;
 
+  // Pings should not be sent if MHTML page is loaded.
+  if (GetDocument().Fetcher()->Archive())
+    return;

[Mike West, 2017/05/02 07:43:21]

What about other things that go through `PingLoader`? (CSP violations, XSS
Auditor violations, Beacon) I guess you're blocking those as well, but it might
make your checks a little more robust to do them there (e.g. in
`SendBeaconCommon`:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/loader/Pi...).

[jianli, 2017/05/03 21:15:17]

I don't think other types of pings/beacons can be triggered from loaded MHTML:
* "report-uri" in Content-Security-Policy cannot be put in meta tag. Thus CSP
violations will not be sent.
* XSS auditor reports can only be triggered by providing XSS protection header
from server. Thus MHTML will not have this problem.
* Navigator.sendBeacon can only be called from the script. Since the script
execution is disabled in MHTML, this will not be likely.

It seems that we only have problem with anchor pings. So I don't want to
complicate PingLoader logic.

+
   UseCounter::Count(GetDocument(), UseCounter::kHTMLAnchorElementPingAttribute);
 
   SpaceSplitString ping_urls(ping_value, SpaceSplitString::kShouldNotFoldCase);