Add new simple disk cache backend.

net/net.gyp

Index: net/net.gyp
diff --git a/net/net.gyp b/net/net.gyp
index c7bf23b70333b546a4efd8fd1318e3702595d0b0..646233d0e93138ee85de0bb27f5b47ef088b3e27 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -7,6 +7,7 @@
     'chromium_code': 1,
 
     'linux_link_kerberos%': 0,
+    'use_very_simple_backend%': 0,

[rvargas (doing something else), 2013/02/06 03:28:40]

do we really need a gyp variable?

[gavinp, 2013/02/08 23:17:51]

Can you tell me more about adding defines without using one? I don't understand
the alternative.

     'conditions': [
       ['chromeos==1 or OS=="android" or OS=="ios"', {
         # Disable Kerberos on ChromeOS, Android and iOS, at least for now.
@@ -52,6 +53,7 @@
         '../sdch/sdch.gyp:sdch',
         '../third_party/icu/icu.gyp:icui18n',
         '../third_party/icu/icu.gyp:icuuc',
+	'../third_party/smhasher/smhasher.gyp:murmurhash3',
         '../third_party/zlib/zlib.gyp:zlib',
         'net_resources',
       ],
@@ -405,6 +407,13 @@
         'disk_cache/stress_support.h',
         'disk_cache/trace.cc',
         'disk_cache/trace.h',
+        'disk_cache/very_simple/very_simple_backend_impl.cc',
+        'disk_cache/very_simple/very_simple_backend_impl.h',
+        'disk_cache/very_simple/very_simple_disk_format.h',
+        'disk_cache/very_simple/very_simple_entry_impl.cc',
+        'disk_cache/very_simple/very_simple_entry_impl.h',
+        'disk_cache/very_simple/very_simple_synchronous_entry.cc',
+        'disk_cache/very_simple/very_simple_synchronous_entry.h',
         'disk_cache/flash/format.h',
         'disk_cache/flash/log_store.cc',
         'disk_cache/flash/log_store.h',
@@ -1029,6 +1038,21 @@
             'dns/dns_client.cc',
           ],
         }],
+	['use_very_simple_backend==1', {
+          'defines': [
+            'USE_VERY_SIMPLE_BACKEND',
+          ]
+        }, { # else
+          'sources!': [

[rvargas (doing something else), 2013/02/06 03:28:40]

why remove these files?

[gavinp, 2013/02/08 23:27:21]

I copied the pattern from what our custom DNS resolver does.

[rvargas (doing something else), 2013/02/13 01:48:46]

I still think this is not the right thing to do... unless you have a strong
reason to avoid compilation of the code by the bots. For example, the flash
backend files compile all the time (and the unit tests run)

+            'disk_cache/very_simple/very_simple_backend_impl.cc',

[pasko-google - do not use, 2013/02/05 21:20:33]

I prefer runtime command-line flag because:
1. no need to gclient runhooks and rebuild, easier to test on bots
2. no ugly ifdefs
3. no repeating ourselves when removing the files conditionally in gyp
4. adds only tiny amount of code

Though it is not a super-strong opinion, I am OK following Ricardo's preference,
I do not know his opinion on it yet

+            'disk_cache/very_simple/very_simple_backend_impl.h',
+            'disk_cache/very_simple/very_simple_disk_format.h',
+            'disk_cache/very_simple/very_simple_entry_impl.cc',
+            'disk_cache/very_simple/very_simple_entry_impl.h',
+            'disk_cache/very_simple/very_simple_synchronous_entry.cc',
+            'disk_cache/very_simple/very_simple_synchronous_entry.h',
+          ],
+        }],
         ['use_openssl==1', {
             'sources!': [
               'base/cert_database_nss.cc',