WebURLRequest: Track the requesting document's URL through navigations.

Source/platform/network/ResourceRequest.cpp

Index: Source/platform/network/ResourceRequest.cpp
diff --git a/Source/platform/network/ResourceRequest.cpp b/Source/platform/network/ResourceRequest.cpp
index 6adc38dc6e2bc6ed92950fef7b76b9844560be31..77ebd417275f9668b4771d0b7d74beea2dfff622 100644
--- a/Source/platform/network/ResourceRequest.cpp
+++ b/Source/platform/network/ResourceRequest.cpp
@@ -40,6 +40,7 @@ PassOwnPtr<ResourceRequest> ResourceRequest::adopt(PassOwnPtr<CrossThreadResourc
     request->setCachePolicy(data->m_cachePolicy);
     request->setTimeoutInterval(data->m_timeoutInterval);
     request->setFirstPartyForCookies(data->m_firstPartyForCookies);
+    request->setRequestorURL(data->m_requestorURL);
     request->setHTTPMethod(AtomicString(data->m_httpMethod));
     request->setPriority(data->m_priority, data->m_intraPriorityValue);
 
@@ -77,6 +78,7 @@ PassOwnPtr<CrossThreadResourceRequestData> ResourceRequest::copyData() const
     data->m_cachePolicy = cachePolicy();
     data->m_timeoutInterval = timeoutInterval();
     data->m_firstPartyForCookies = firstPartyForCookies().copy();
+    data->m_requestorURL = requestorURL().copy();
     data->m_httpMethod = httpMethod().string().isolatedCopy();
     data->m_httpHeaders = httpHeaderFields().copyData();
     data->m_priority = priority();
@@ -167,6 +169,16 @@ void ResourceRequest::setFirstPartyForCookies(const KURL& firstPartyForCookies)
     m_firstPartyForCookies = firstPartyForCookies;
 }
 
+const KURL& ResourceRequest::requestorURL() const
+{
+    return m_requestorURL;
+}
+
+void ResourceRequest::setRequestorURL(const KURL& requestorURL)
+{
+    m_requestorURL = requestorURL;
+}
+
 const AtomicString& ResourceRequest::httpMethod() const
 {
     return m_httpMethod;
@@ -324,6 +336,9 @@ bool equalIgnoringHeaderFields(const ResourceRequest& a, const ResourceRequest&
     if (a.firstPartyForCookies() != b.firstPartyForCookies())
         return false;
 
+    if (a.requestorURL() != b.requestorURL())

[jochen (gone - plz use gerrit), 2015/04/13 13:07:02]

my main concern is whether this will negatively impact cache hit rates

[Mike West, 2015/04/21 12:46:23]

That's a fair concern. I suppose we can drop this bit for now, and allow
coalescing requests for the same resource. If we end up with interesting
policies associated with the requestor, however, we'd need to break the caching
link. :/

+        return false;
+
     if (a.httpMethod() != b.httpMethod())
         return false;