Override server-side simple-cache trial with commandline switches.

FIXING broken about:flags for simple cache on Android.

Until recently we used a trick to avoid dedicated global settings in
net::disk_cache other than the objects belonging to the infrastructure of the
trials. The commandline flag would change the experiment group on the chromium
side, while one the net/ side we would check which group we belong to.

Later we decided to switch to the server-controlled experiments. This went into
a conflict with our approach: the server-controlled experiment would override
the settings set by the command-line option. This is unfortunate.

Stevet@ suggests that there are plans to avoid overriding the experiment groups
by the server config, but in the meantime the trick stops working.

Solve this by adding backend type enum provided at backend instantiation.

TBR=jam@chromium.org
BUG=239461

Review URL: https://chromiumcodereview.appspot.com/14828004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@199708 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 11 insertions, 4 deletions

diff --git a/net/http/http_cache.cc b/net/http/http_cache.cc
index 421300e..8905695 100644
--- a/net/http/http_cache.cc
+++ b/net/http/http_cache.cc
@@ -27,6 +27,7 @@
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/threading/worker_pool.h"
+#include "net/base/cache_type.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
@@ -52,10 +53,12 @@ void DeletePath(base::FilePath path) {
 namespace net {
 
 HttpCache::DefaultBackend::DefaultBackend(CacheType type,
+                                          BackendType backend_type,
                                           const base::FilePath& path,
                                           int max_bytes,
                                           base::MessageLoopProxy* thread)
     : type_(type),
+      backend_type_(backend_type),
       path_(path),
       max_bytes_(max_bytes),
       thread_(thread) {
@@ -65,15 +68,17 @@ HttpCache::DefaultBackend::~DefaultBackend() {}
 
 // static
 HttpCache::BackendFactory* HttpCache::DefaultBackend::InMemory(int max_bytes) {
-  return new DefaultBackend(MEMORY_CACHE, base::FilePath(), max_bytes, NULL);
+  return new DefaultBackend(MEMORY_CACHE, net::CACHE_BACKEND_DEFAULT,
+                            base::FilePath(), max_bytes, NULL);
 }
 
 int HttpCache::DefaultBackend::CreateBackend(
     NetLog* net_log, disk_cache::Backend** backend,
     const CompletionCallback& callback) {
   DCHECK_GE(max_bytes_, 0);
-  return disk_cache::CreateCacheBackend(type_, path_, max_bytes_, true,
-                                        thread_, net_log, backend, callback);
+  return disk_cache::CreateCacheBackend(type_, backend_type_, path_, max_bytes_,
+                                        true, thread_, net_log, backend,
+                                        callback);
 }
 
 //-----------------------------------------------------------------------------
diff --git a/net/http/http_cache.h b/net/http/http_cache.h
index 9e6b73c..fcba80e 100644
--- a/net/http/http_cache.h
+++ b/net/http/http_cache.h
@@ -99,7 +99,8 @@ class NET_EXPORT HttpCache : public HttpTransactionFactory,
     // |path| is the destination for any files used by the backend, and
     // |cache_thread| is the thread where disk operations should take place. If
     // |max_bytes| is  zero, a default value will be calculated automatically.
-    DefaultBackend(CacheType type, const base::FilePath& path, int max_bytes,
+    DefaultBackend(CacheType type, BackendType backend_type,
+                   const base::FilePath& path, int max_bytes,
                    base::MessageLoopProxy* thread);
     virtual ~DefaultBackend();
 
@@ -113,6 +114,7 @@ class NET_EXPORT HttpCache : public HttpTransactionFactory,
 
    private:
     CacheType type_;
+    BackendType backend_type_;
     const base::FilePath path_;
     int max_bytes_;
     scoped_refptr<base::MessageLoopProxy> thread_;