Remove incorrect language indicating that URLRequest was dependent on SDCHOwner.

net/sdch/README.md

 # SDCH 
 
 "SDCH" stands for "Shared Dictionary Compression over HTTP".  It is a
 protocol for compressing URL responses used when the server and
 the client share a dictionary that can be referred to for
 compression/encoding and decompression/decoding.  The details of the
 SDCH protocol are specified in 
 [the spec](https://docs.google.com/a/chromium.org/document/d/1REMkwjXY5yFOkJwtJPjCMwZ4Shx3D9vfdAytV_KQCUo/edit?pli=1)
 (soon to be moved to github) but in brief:
 
@@ skipping 45 matching lines @@
   dictionaries in response to new fetches, and constraints on the
   amount of memory that is usable by SDCH dictionaries.  It initiates
   dictionary fetches as appropriate when it receives notification of
   a "Get-Dictionary" header from the SdchManager.
 
 A net/ embedder should instantiate an SdchManager and an SdchOwner,
 and guarantee that the SdchManager outlive the SdchOwner.
 
 Note the layering of the above classes:
 
-1. The SdchManager and SdchOwner classes have no knowledge of
-   URLRequests.  URLRequest is dependent on those classes, not the
-   reverse.
+1. The SdchManager class has no knowledge of URLRequests.  URLRequest
+   is dependent on that class, not the reverse.
 2. SdchDictionaryFetcher is dependent on URLRequest, but is still a
    utility class exported by the net/ library for use by higher levels.
 3. SdchOwner manages the entire system on behalf of the embedder.  The
    intent is that the embedder can change policies through methods on
    SdchOwner, while letting the SdchOwner class take care of policy
    implementation. 
 
 ## SDCH in Chromium: Debugging
 
 Data that is useful in debugging SDCH problems:
@@ skipping 31 matching lines @@
   the server in question, temporarily (if it can recover that request)
   or permanently (if it can't).  This can lead to a mysterious lack of
   SDCH encoding when it's expected to be present.
 * The network cache currently stores the response precisely as received from
   the network.  This means that requests that don't advertise SDCH
   may get a cached value that is SDCH encoded, and requests that do
   advertise SDCH may get a cached value that is not SDCH encoded.
   The second case is handled transparently, but the first case may
   lead to request failure.