Revert of Include class relationship diagrams in network stack documentation.

net/docs/life-of-a-url-request.md

Index: net/docs/life-of-a-url-request.md
diff --git a/net/docs/life-of-a-url-request.md b/net/docs/life-of-a-url-request.md
index 4de3567f9922200f4b6b1605ada57a5f1a436122..63f55f698bc86cad278b4d585d866a141d423aaa 100644
--- a/net/docs/life-of-a-url-request.md
+++ b/net/docs/life-of-a-url-request.md
@@ -293,24 +293,6 @@
 socket pool, either for reuse or so the socket pool knows it has another free
 socket slot.
 
-### Object Relationships and Ownership
-
-A sample of the object relationships involved in the above process is
-diagramed here: 
-
-![Object Relationship Diagram for URLRequest lifetime](url_request.svg)
-
-There are a couple of points in the above diagram that do not come
-clear visually:
-
-* The method that generates the filter chain that is hung off the
-  URLRequestJob is declared on URLRequestJob, but the only current
-  implementation of it is on URLRequestHttpJob, so the generation is
-  shown as happening from that class.
-* HttpTransactions of different types are layered; i.e. a
-  HttpCache::Transaction contains a pointer to an HttpTransaction, but
-  that pointed-to HttpTransaction generally is an
-  HttpNetworkTransaction. 
 
 # Additional Topics
 
@@ -436,33 +418,6 @@
 instance, SSL and HTTP connections won't be grouped together in the
 TcpClientSocketPool, which the SSLClientSocketPool sits on top of.
 
-### Socket Pool Class Relationships
-
-The relationships between the important classes in the socket pools is
-shown diagrammatically for the lowest layer socket pool
-(TransportSocketPool) below. 
-
-![Object Relationship Diagram for Socket Pools](pools.svg)
-
-The ClientSocketPoolBase is a template class templatized on the class
-containing the parameters for the appropriate type of socket (in this
-case TransportSocketParams).  It contains a pointer to the
-ClientSocketPoolBaseHelper, which contains all the type-independent
-machinery of the socket pool.  
-
-When socket pools are initialized, they in turn initialize their
-templatized ClientSocketPoolBase member with an object with which it
-should create connect jobs.  That object must derive from
-ClientSocketPoolBase::ConnectJobFactory templatized by the same type
-as the ClientSocketPoolBase.  (In the case of the diagram above, that
-object is a TransportConnectJobFactory, which derives from
-ClientSocketPoolBase::ConnectJobFactory<TransportSocketParams>.)
-Internally, that object is wrapped in a type-unsafe wrapper
-(ClientSocketPoolBase::ConnectJobFactoryAdaptor) so that it can be
-passed to the initialization of the ClientSocketPoolBaseHelper.  This
-allows the helper to create connect jobs while preserving a type-safe
-API to the initialization of the socket pool.
-
 ### SSL
 
 When an SSL connection is needed, the ClientSocketPoolManager assembles the