Make the blockfile cache an optional build product for chrome target.

net/net.gyp

Index: net/net.gyp
diff --git a/net/net.gyp b/net/net.gyp
index c192286995bc5a2ff434cb2ab1774926a70f68de..6f1aa33717dc0e72872d1b7edcdbf4966d60dcbd 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -7,6 +7,7 @@
     'chromium_code': 1,
 
     'linux_link_kerberos%': 0,
+    'use_blockfile_cache_backend%': 1,
     'use_tracing_cache_backend%': 0,
     'conditions': [
       ['chromeos==1 or embedded==1 or OS=="android" or OS=="ios"', {
@@ -1332,11 +1333,18 @@
             'dns/dns_client.cc',
           ],
         }],
+	['use_blockfile_cache_backend==1', {
+	  'defines': [
+	    'USE_BLOCKFILE_CACHE_BACKEND',
+	  ],
+	}, { # use_blockfile_cache_backend == 0
+	  'sources/': [ ['exclude', '^disk_cache/v[23]/' ] ]

[rvargas (doing something else), 2014/02/06 05:09:28]

I'm not sure about excluding v3. I've been leaning towards not excluding it
lately.

Also, I don't think in general we use patterns to exclude/include files on gyp
files (other than the platform specific ones). I would have guessed we want to
be absolutely explicit about what files are part of a target. Matching patterns
from cs or similar doesn't work.

[gavinp, 2014/02/09 15:29:37]

Can you expand on that?
What is "cs or similar"?

This pattern works here, because the directory organization was chosen
specifically to support it, though; it is absolutely explicit because placement
in a directory means exactly that.

Explicitly listing carries the downside that there's two lists to keep precisely
in sync.  Someone will get that wrong very quickly if we go to it.

+        }],
         ['use_tracing_cache_backend==1', {
           'defines': [
             'USE_TRACING_CACHE_BACKEND'
           ],
-         }],
+        }],
         ['use_openssl==1', {
             'sources!': [
               'base/crypto_module_nss.cc',