Introduces a new MHTML generation parameter specifying different behvaior for cache-control headers.

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 09fab010910923bea9bed94a704d40d0052a75d2..5349d4f5b1e1dd6e13837621961f6cdd748b3a67 100644
--- a/third_party/WebKit/Source/web/WebFrameSerializer.cpp
+++ b/third_party/WebKit/Source/web/WebFrameSerializer.cpp
@@ -47,10 +47,13 @@
 #include "platform/SharedBuffer.h"
 #include "platform/mhtml/MHTMLArchive.h"
 #include "platform/mhtml/MHTMLParser.h"
+#include "platform/network/ResourceResponse.h"
 #include "platform/weborigin/KURL.h"
 #include "public/platform/WebString.h"
 #include "public/platform/WebURL.h"
+#include "public/platform/WebURLResponse.h"
 #include "public/platform/WebVector.h"
+#include "public/web/WebDataSource.h"
 #include "public/web/WebDocument.h"
 #include "public/web/WebFrame.h"
 #include "public/web/WebFrameSerializerClient.h"
@@ -136,18 +139,37 @@ bool MHTMLFrameSerializerDelegate::shouldSkipResource(const KURL& url)
     return m_webDelegate.shouldSkipResource(url);
 }
 
+bool resourceResponseContainsNoStore(const ResourceResponse& response)
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, cacheControlHeader, ("cache-control"));
+    DEFINE_STATIC_LOCAL(const AtomicString, pragmaHeader, ("pragma"));
+
+    return parseCacheControlDirectives(
+        response.httpHeaderField(cacheControlHeader),
+        response.httpHeaderField(pragmaHeader)).containsNoStore;

[Łukasz Anforowicz, 2016/05/12 18:56:49]

Could this be written as:
return response.cacheControlContainsNoStore();
?

[dewittj, 2016/05/12 22:58:01]

No, that method is not const, since it caches the results of parsing the cache
control header.

I was unable to figure out a way to get a non-const ResourceResponse; if you
have ideas I'd be glad to hear!

[Łukasz Anforowicz, 2016/05/12 23:56:27]

Oh, indeed - thanks for the explanation.  And I see that this constness problem
also happens in the Blink's core layer (i.e. blink::DocumentLoader::response()
returns a const-ref to ResourceResponse).

I hope that Blink owners can help here - it feels weird (wrong?) to me to repeat
the parsing call here, but maybe it is okay, given constness constraints?

[dcheng, 2016/05/13 17:48:33]

+toyoshim, +hiroshige: any ideas on how to improve this so we don't need to
manually reparse here?

[hiroshige, 2016/05/13 18:01:52]

How about making ResourceResponse::cacheControlContainsNoCache() and similar
methods to be const by making |ResourceResponse::m_cacheControlHeader| mutable,
and calling response.cacheControlContainsNoStore() here?

+}
+
 } // namespace
 
-WebData WebFrameSerializer::generateMHTMLHeader(
-    const WebString& boundary, WebLocalFrame* frame)
+bool WebFrameSerializer::generateMHTMLHeader(
+    const WebString& boundary, CacheControlPolicy cacheControlPolicy,
+    WebLocalFrame* frame, WebData* data)
 {
-    Document* document = toWebLocalFrameImpl(frame)->frame()->document();
+    WebLocalFrameImpl* webLocalFrameImpl = toWebLocalFrameImpl(frame);
+    DCHECK(webLocalFrameImpl);
+
+    const ResourceResponse& response = webLocalFrameImpl->dataSource()->response().toResourceResponse();
+    if (cacheControlPolicy == CacheControlPolicyFailForNoStoreMainFrame && resourceResponseContainsNoStore(response))
+        return false;
+
+    Document* document = webLocalFrameImpl->frame()->document();
 
     RefPtr<SharedBuffer> buffer = SharedBuffer::create();
     MHTMLArchive::generateMHTMLHeader(
         boundary, document->title(), document->suggestedMIMEType(),
         *buffer);
-    return buffer.release();
+    *data = buffer.release();
+    return true;
 }
 
 WebData WebFrameSerializer::generateMHTMLParts(