Add a new GetInstance() method for singleton classes under chrome/service and /net.

This is a small step towards making all singleton classes use the Singleton<T> pattern within their code and not expect the callers to know about it.

This CL includes files under chrome/service and /net with related files elsewhere.

Suggested files to focus for reviewers:
- @sanjeevr for chrome/common and chrome/service
- @ukai for net/websockets
- @agl for rest of net

BUG=65298
TEST=all existing tests should continue to pass.

Review URL: http://codereview.chromium.org/5634005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68722 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 20 insertions, 10 deletions

diff --git a/net/websockets/websocket_job.cc b/net/websockets/websocket_job.cc
index a1e2dde..9adbaa3 100644
--- a/net/websockets/websocket_job.cc
+++ b/net/websockets/websocket_job.cc
@@ -6,6 +6,7 @@
 
 #include <algorithm>
 
+#include "base/singleton.h"
 #include "base/string_tokenizer.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/net_errors.h"
@@ -144,8 +145,8 @@ void WebSocketJob::RestartWithAuth(
 
 void WebSocketJob::DetachDelegate() {
   state_ = CLOSED;
-  Singleton<WebSocketThrottle>::get()->RemoveFromQueue(this);
-  Singleton<WebSocketThrottle>::get()->WakeupSocketIfNecessary();
+  WebSocketThrottle::GetInstance()->RemoveFromQueue(this);
+  WebSocketThrottle::GetInstance()->WakeupSocketIfNecessary();
 
   scoped_refptr<WebSocketJob> protect(this);
 
@@ -165,7 +166,7 @@ int WebSocketJob::OnStartOpenConnection(
   DCHECK(!callback_);
   state_ = CONNECTING;
   addresses_.Copy(socket->address_list().head(), true);
-  Singleton<WebSocketThrottle>::get()->PutInQueue(this);
+  WebSocketThrottle::GetInstance()->PutInQueue(this);
   if (!waiting_)
     return OK;
   callback_ = callback;
@@ -237,8 +238,8 @@ void WebSocketJob::OnReceivedData(
 
 void WebSocketJob::OnClose(SocketStream* socket) {
   state_ = CLOSED;
-  Singleton<WebSocketThrottle>::get()->RemoveFromQueue(this);
-  Singleton<WebSocketThrottle>::get()->WakeupSocketIfNecessary();
+  WebSocketThrottle::GetInstance()->RemoveFromQueue(this);
+  WebSocketThrottle::GetInstance()->WakeupSocketIfNecessary();
 
   scoped_refptr<WebSocketJob> protect(this);
 
@@ -405,8 +406,8 @@ void WebSocketJob::SaveNextCookie() {
 
     handshake_response_.reset();
 
-    Singleton<WebSocketThrottle>::get()->RemoveFromQueue(this);
-    Singleton<WebSocketThrottle>::get()->WakeupSocketIfNecessary();
+    WebSocketThrottle::GetInstance()->RemoveFromQueue(this);
+    WebSocketThrottle::GetInstance()->WakeupSocketIfNecessary();
     return;
   }
 
diff --git a/net/websockets/websocket_job_unittest.cc b/net/websockets/websocket_job_unittest.cc
index 53d4a625..43d8509 100644
--- a/net/websockets/websocket_job_unittest.cc
+++ b/net/websockets/websocket_job_unittest.cc
@@ -222,7 +222,7 @@ class WebSocketJobTest : public PlatformTest {
     addr.ai_addr = reinterpret_cast<sockaddr*>(&sa_in);
     addr.ai_next = NULL;
     websocket_->addresses_.Copy(&addr, true);
-    Singleton<WebSocketThrottle>::get()->PutInQueue(websocket_);
+    WebSocketThrottle::GetInstance()->PutInQueue(websocket_);
   }
   WebSocketJob::State GetWebSocketJobState() {
     return websocket_->state_;
@@ -230,7 +230,7 @@ class WebSocketJobTest : public PlatformTest {
   void CloseWebSocketJob() {
     if (websocket_->socket_) {
       websocket_->socket_->DetachDelegate();
-      Singleton<WebSocketThrottle>::get()->RemoveFromQueue(websocket_);
+      WebSocketThrottle::GetInstance()->RemoveFromQueue(websocket_);
     }
     websocket_->state_ = WebSocketJob::CLOSED;
     websocket_->delegate_ = NULL;
diff --git a/net/websockets/websocket_throttle.cc b/net/websockets/websocket_throttle.cc
index 2d62815..c714de6 100644
--- a/net/websockets/websocket_throttle.cc
+++ b/net/websockets/websocket_throttle.cc
@@ -54,6 +54,11 @@ WebSocketThrottle::~WebSocketThrottle() {
   DCHECK(addr_map_.empty());
 }
 
+// static
+WebSocketThrottle* WebSocketThrottle::GetInstance() {
+  return Singleton<WebSocketThrottle>::get();
+}
+
 void WebSocketThrottle::PutInQueue(WebSocketJob* job) {
   queue_.push_back(job);
   const AddressList& address_list = job->address_list();
diff --git a/net/websockets/websocket_throttle.h b/net/websockets/websocket_throttle.h
index 0849834..9becc62 100644
--- a/net/websockets/websocket_throttle.h
+++ b/net/websockets/websocket_throttle.h
@@ -10,7 +10,8 @@
 #include <string>
 
 #include "base/hash_tables.h"
-#include "base/singleton.h"
+
+template <typename T> struct DefaultSingletonTraits;
 
 namespace net {
 
@@ -27,6 +28,9 @@ class WebSocketJob;
 //        for that connection to have failed.
 class WebSocketThrottle {
  public:
+  // Returns the singleton instance.
+  static WebSocketThrottle* GetInstance();
+
   // Puts |job| in |queue_| and queues for the destination addresses
   // of |job|.
   // If other job is using the same destination address, set |job| waiting.