[CrOS Tether] Add a factory to CrashRecoveryManager.

This will be used to aid testing in a follow-up CL.

Bug: 761532, 672263
Change-Id: Icd54139447b13f6a8ec1feb6f4345701ff4e115d
Reviewed-on: https://chromium-review.googlesource.com/724080Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509565}

chromeos/components/tether/crash_recovery_manager.cc

@@ -5,6 +5,7 @@
 #include "chromeos/components/tether/crash_recovery_manager.h"
 
 #include "base/bind.h"
+#include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
 #include "chromeos/components/tether/host_scan_cache.h"
 #include "chromeos/network/network_state.h"
@@ -16,6 +17,37 @@ namespace chromeos {
 
 namespace tether {
 
+// static
+CrashRecoveryManager::Factory*
+    CrashRecoveryManager::Factory::factory_instance_ = nullptr;
+
+// static
+std::unique_ptr<CrashRecoveryManager>
+CrashRecoveryManager::Factory::NewInstance(
+    NetworkStateHandler* network_state_handler,
+    ActiveHost* active_host,
+    HostScanCache* host_scan_cache) {
+  if (!factory_instance_)
+    factory_instance_ = new Factory();
+
+  return factory_instance_->BuildInstance(network_state_handler, active_host,
+                                          host_scan_cache);
+}
+
+// static
+void CrashRecoveryManager::Factory::SetInstanceForTesting(Factory* factory) {
+  factory_instance_ = factory;
+}
+
+std::unique_ptr<CrashRecoveryManager>
+CrashRecoveryManager::Factory::BuildInstance(
+    NetworkStateHandler* network_state_handler,
+    ActiveHost* active_host,
+    HostScanCache* host_scan_cache) {
+  return base::MakeUnique<CrashRecoveryManager>(network_state_handler,
+                                                active_host, host_scan_cache);
+}
+
 CrashRecoveryManager::CrashRecoveryManager(
     NetworkStateHandler* network_state_handler,
     ActiveHost* active_host,

chromeos/components/tether/crash_recovery_manager.h

@@ -22,6 +22,25 @@ class HostScanCache;
 // Restores Tether state after a browser crash.
 class CrashRecoveryManager {
  public:
+  class Factory {
+   public:
+    static std::unique_ptr<CrashRecoveryManager> NewInstance(
+        NetworkStateHandler* network_state_handler,
+        ActiveHost* active_host,
+        HostScanCache* host_scan_cache);
+
+    static void SetInstanceForTesting(Factory* factory);
+
+   protected:
+    virtual std::unique_ptr<CrashRecoveryManager> BuildInstance(
+        NetworkStateHandler* network_state_handler,
+        ActiveHost* active_host,
+        HostScanCache* host_scan_cache);
+
+   private:
+    static Factory* factory_instance_;
+  };
+
   CrashRecoveryManager(NetworkStateHandler* network_state_handler,
                        ActiveHost* active_host,
                        HostScanCache* host_scan_cache);