Simple Cache: Add two optional stream 2 histograms

net/disk_cache/simple/simple_entry_impl.cc

Index: net/disk_cache/simple/simple_entry_impl.cc
diff --git a/net/disk_cache/simple/simple_entry_impl.cc b/net/disk_cache/simple/simple_entry_impl.cc
index 3d2bc22cc36688d70b6f6f457252fcddd2f9edeb..be7788b89b9da5582f82bc5003f9373517694852 100644
--- a/net/disk_cache/simple/simple_entry_impl.cc
+++ b/net/disk_cache/simple/simple_entry_impl.cc
@@ -1296,8 +1296,8 @@ int SimpleEntryImpl::SetStream0Data(net::IOBuffer* buf,
                                     int buf_len,
                                     bool truncate) {
   // Currently, stream 0 is only used for HTTP headers, and always writes them
-  // with a single, truncating write.  Detect these writes and record the size
-  // changes of the headers.  Also, support writes to stream 0 that have
+  // with a single, truncating write. Detect these writes and record the size
+  // changes of the headers. Also, support writes to stream 0 that have
   // different access patterns, as required by the API contract.
   // All other clients of the Simple Cache are encouraged to use stream 1.
   have_written_[0] = true;