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

third_party/WebKit/public/web/WebFrameSerializer.h

Index: third_party/WebKit/public/web/WebFrameSerializer.h
diff --git a/third_party/WebKit/public/web/WebFrameSerializer.h b/third_party/WebKit/public/web/WebFrameSerializer.h
index ecf4acfbf639421962af3284cc66d21db20e2c70..221cf54cf0bdb205e59ec3bb9175184a01241fdb 100644
--- a/third_party/WebKit/public/web/WebFrameSerializer.h
+++ b/third_party/WebKit/public/web/WebFrameSerializer.h
@@ -47,6 +47,15 @@ template <typename T> class WebVector;
 // Serialization of frame contents into html or mhtml.
 class WebFrameSerializer {
 public:
+    // By default, frame serialization encompasses all resources in a page.  If it
+    // is desirable to serialize only those resources that could be stored by a http
+    // cache, the other options may be used.
+    // FIXME: Add more policies for subframes and subresources.

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

nit: I've been told by other reviewers to prefer TODO(alias) + to refer to a bug
:-)

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

Done.

+    enum CacheControlPolicy {
+        CacheControlPolicyIgnore,
+        CacheControlPolicyFailForNoStoreMainFrame
+    };
+
     // Generates and returns an MHTML header.

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

nit: This should describe the new return value / talk about returning the header
contents via the last parameter.

[dewittj, 2016/05/12 22:58:02]

Done.

     //
     // Contents of the header (i.e. title and mime type) will be based
@@ -56,8 +65,9 @@ public:
     // Same |boundary| needs to used for all generateMHTMLHeader and
     // generateMHTMLParts and generateMHTMLFooter calls that belong to the same
     // MHTML document (see also rfc1341, section 7.2.1, "boundary" description).
-    BLINK_EXPORT static WebData generateMHTMLHeader(
-        const WebString& boundary, WebLocalFrame*);
+    BLINK_EXPORT static bool generateMHTMLHeader(
+        const WebString& boundary, CacheControlPolicy, WebLocalFrame*,
+        WebData*);
 
     // Delegate for controling the behavior of generateMHTMLParts method.
     class MHTMLPartsGenerationDelegate {