Don't crash when navigating an OOPIF to a URL that fails.

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index 266ae71c59f457ce33f0b54f8cdd2356c39f815d..f07d3b7916e8ab82b6dce4cb43039b345f988841 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -1210,8 +1210,8 @@ void FrameLoader::receivedMainResourceError(DocumentLoader* loader, const Resour
     ResourceError c(ResourceError::cancelledError(KURL()));
     if ((error.errorCode() != c.errorCode() || error.domain() != c.domain()) && m_frame->owner()) {
         // FIXME: For now, fallback content doesn't work cross process.

[Charlie Reis, 2016/01/28 00:51:37]

Is this FIXME still needed?  The network error page does show up in the subframe
after this fix, so I'm not sure whether the fallback content is broken or not.

[Nate Chapin, 2016/01/28 00:56:08]

Fallback content in this sense is, e.g., an image that gets displayed when a
plugin fails to load. I don't think that's what you're talking about?

[Charlie Reis, 2016/01/28 01:02:17]

Ok, that sounds like something else.  I'll leave the FIXME in case it matters
for another case.

-        ASSERT(m_frame->owner()->isLocal());
-        m_frame->deprecatedLocalOwner()->renderFallbackContent();
+        if (m_frame->owner()->isLocal())
+            m_frame->deprecatedLocalOwner()->renderFallbackContent();
     }
 
     HistoryCommitType historyCommitType = loadTypeToCommitType(m_loadType);