PlzNavigate: make MHTML iframe load working.

third_party/WebKit/Source/web/LocalFrameClientImpl.h

Index: third_party/WebKit/Source/web/LocalFrameClientImpl.h
diff --git a/third_party/WebKit/Source/web/LocalFrameClientImpl.h b/third_party/WebKit/Source/web/LocalFrameClientImpl.h
index 43bc8445608cc56cb563609c492a0f024a1278eb..a67c12911d78dc067ebf59c64174c4b4b1690ea9 100644
--- a/third_party/WebKit/Source/web/LocalFrameClientImpl.h
+++ b/third_party/WebKit/Source/web/LocalFrameClientImpl.h
@@ -228,6 +228,11 @@ class LocalFrameClientImpl final : public LocalFrameClient {
   bool IsLocalFrameClientImpl() const override { return true; }
   WebDevToolsAgentImpl* DevToolsAgent();
 
+  // An MHTML Archive is a set of resources, including iframes, that is parsed
+  // as a whole. This function tells whether of not an archive exists and should
+  // be used for loading a subframe.
+  bool ShouldUseMHTMLArchiveForSubFrame() const;

[jianli, 2017/05/03 22:56:19]

When an archive exist, we should always use it to load a subframe. So probably
it is better to name this method as something like IsLoadedAsMHTMLArchive?

Note that exposing this is very useful in probably helping other business,
consider we might want to add some mhtml specific logic in renderer client. So I
would like to see this name be more generic.

[arthursonzogni, 2017/05/04 14:26:32]

Done.

+
   // The WebFrame that owns this object and manages its lifetime. Therefore,
   // the web frame object is guaranteed to exist.
   Member<WebLocalFrameImpl> web_frame_;