[Proximity Auth] Create one ProximityAuthClient per profile, rather than one global one.

chrome/browser/extensions/api/screenlock_private/screenlock_private_api.cc

Index: chrome/browser/extensions/api/screenlock_private/screenlock_private_api.cc
diff --git a/chrome/browser/extensions/api/screenlock_private/screenlock_private_api.cc b/chrome/browser/extensions/api/screenlock_private/screenlock_private_api.cc
index b55a9cb74b11df28ad9d26eafc3856ea233e16cf..cc2001833a4ea4de0a54d18725c614afc3589fb0 100644
--- a/chrome/browser/extensions/api/screenlock_private/screenlock_private_api.cc
+++ b/chrome/browser/extensions/api/screenlock_private/screenlock_private_api.cc
@@ -7,6 +7,7 @@
 #include "base/lazy_instance.h"
 #include "base/values.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/signin/chrome_proximity_auth_client.h"
 #include "chrome/browser/signin/easy_unlock_service.h"
 #include "chrome/browser/signin/proximity_auth_facade.h"
 #include "chrome/common/extensions/api/screenlock_private.h"
@@ -65,6 +66,7 @@ bool ScreenlockPrivateSetLockedFunction::RunAsync() {
   scoped_ptr<screenlock::SetLocked::Params> params(
       screenlock::SetLocked::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
+  EasyUnlockService* service = EasyUnlockService::Get(GetProfile());
   if (params->locked) {
     if (extension()->id() == extension_misc::kEasyUnlockAppId &&
         AppWindowRegistry::Get(browser_context())
@@ -73,13 +75,12 @@ bool ScreenlockPrivateSetLockedFunction::RunAsync() {
       // Mark the Easy Unlock behaviour on the lock screen as the one initiated
       // by the Easy Unlock setup app as a trial one.
       // TODO(tbarzic): Move this logic to a new easyUnlockPrivate function.
-      EasyUnlockService* service = EasyUnlockService::Get(GetProfile());
-      if (service)
-        service->SetTrialRun();
+      service->SetTrialRun();
     }
-    GetScreenlockBridgeInstance()->Lock(GetProfile());
+    GetScreenlockBridgeInstance()->Lock();
   } else {
-    GetScreenlockBridgeInstance()->Unlock(GetProfile());
+    GetScreenlockBridgeInstance()->Unlock(
+        service->proximity_auth_client()->GetAuthenticatedUsername());

[Marijn Kruisselbrink, 2015/06/29 18:15:04]

Can you add a comment to that Unlock method to describe what the user_email
parameter is/what it is used for? Reading this code and the interface it calls I
have no idea why it is passing some seemingly arbitrary "username" to a method
expecting a "user_email". Or would it make sense for Unlock to take the
proximity_auth_client() and get whatever it needs to get from there itself?

[Ilya Sherman, 2015/06/30 00:22:00]

Done, though I'm not sure how much it helps.  I think the confusion stems from
the fact that the identifier is called a username in some places in the code,
and an email address in others.  So, this method implementation is a bit
surprising:
https://code.google.com/p/chromium/codesearch#chromium/src/components/signin/...

[Ilya Sherman, 2015/06/30 01:36:58]

To address the other part of your reply: Tim specifically asked me *not* to pass
the proximity_auth_client to Unlock, so as to reduce coupling.  There's some
chance we'll want to extract the ScreenlockBridge class outside of the
proximity_auth component later on.

   }
   SendResponse(error_.empty());
   return true;