Remove PermissionContext factories

chrome/browser/permissions/permission_manager.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_PERMISSIONS_PERMISSION_MANAGER_H_
 #define CHROME_BROWSER_PERMISSIONS_PERMISSION_MANAGER_H_
 
+#include <map>
+
 #include "base/callback_forward.h"
 #include "base/id_map.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "components/content_settings/core/browser/content_settings_observer.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "content/public/browser/permission_manager.h"
 
+class PermissionContextBase;
 class Profile;
 
 namespace content {
 enum class PermissionType;
 class WebContents;
 };  // namespace content
 
 class PermissionManager : public KeyedService,
                           public content::PermissionManager,
                           public content_settings::Observer {
  public:
   explicit PermissionManager(Profile* profile);
   ~PermissionManager() override;
 
+  PermissionContextBase* GetPermissionContext(content::PermissionType type);

[mlamouri (slow - plz ping), 2016/04/11 14:06:05]

I would love this to go away actually. No need to do it in this CL but given
that PermissionManager is the entry point for PermissionContext, I think we
should be able to force PermissionManager to be used instead of getting the
PermissionContext. WDYT? Maybe you could add a TODO here?

(Obviously, when I say go away, I mean becomes private for internal and test
usage.)

[raymes, 2016/04/12 07:44:54]

I agree. I managed to change all the occurrences in prod code except in
media_permission. I made MediaPermission a friend class (with a TODO) in order
to make this private. Alternatively I can just leave it public. Let me know.

+
   // content::PermissionManager implementation.
   int RequestPermission(
       content::PermissionType permission,
       content::RenderFrameHost* render_frame_host,
       const GURL& requesting_origin,
       const base::Callback<void(blink::mojom::PermissionStatus)>& callback)
       override;
   int RequestPermissions(
       const std::vector<content::PermissionType>& permissions,
       content::RenderFrameHost* render_frame_host,
@@ skipping 45 matching lines @@
   // content_settings::Observer implementation.
   void OnContentSettingChanged(const ContentSettingsPattern& primary_pattern,
                                const ContentSettingsPattern& secondary_pattern,
                                ContentSettingsType content_type,
                                std::string resource_identifier) override;
 
   Profile* profile_;
   PendingRequestsMap pending_requests_;
   SubscriptionsMap subscriptions_;
 
+  std::map<content::PermissionType, scoped_ptr<PermissionContextBase>>
+      permission_contexts_;

[mlamouri (slow - plz ping), 2016/04/11 14:06:05]

What about:
std::unordered_map<content::PermissionType,
std::unique_ptr<PermissionContextBase>> ?

[raymes, 2016/04/12 07:44:54]

I tried this but got a bunch of link errors because there is no hash function
for PermissionType. I can look into this more tomorrow.

[mlamouri (slow - plz ping), 2016/04/12 11:36:39]

Would that help to do `enum class PermissionType :char`? Otherwise, I guess you
could implement the hash function (should be trivial). Worse case, why not using
std::vector. It's an enum and nearly all values are used so we could simply do
random access.

[raymes, 2016/04/13 00:35:07]

Unfortunately doing enum class PermissionType : char didn't work. It seems like
this is fixed in c++ 14.

For now I defined a simple hash in PermissionManager. We could move it out if it
gets used more broadly. Does that seem ok?

+
   base::WeakPtrFactory<PermissionManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PermissionManager);
 };
 
 #endif // CHROME_BROWSER_PERMISSIONS_PERMISSION_MANAGER_H_