Refactoring: de-couple Extensions from "script injection System" [render side] : 1

extensions/common/host_id.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 EXTENSIONS_COMMON_HOST_ID_H_
 #define EXTENSIONS_COMMON_HOST_ID_H_
 
 #include <string>
 
+#include "base/macros.h"
+#include "extensions/common/permissions/permissions_data.h"
+#include "url/gurl.h"
+
 // IDs of hosts who own user scripts.
 // A HostID is immutable after creation.
 struct HostID {
   enum HostType { EXTENSIONS, WEBUI };
 
   HostID() {}
   HostID(HostType type, const std::string& id)
       : type_(type), id_(id) {}
+  HostID(const HostID& host_id)
+      : type_(host_id.type()),
+        id_(host_id.id()) {}
 
   bool operator<(const HostID& host_id) const {
     if (type_ != host_id.type())
       return type_ < host_id.type();
     else if (id_ != host_id.id())
       return id_ < host_id.id();
     return false;
   }
 
+  bool operator==(const HostID& host_id) const {
+    return type_ == host_id.type() && id_ == host_id.id();
+  }
+
   HostType type() const { return type_; }
   const std::string& id() const { return id_; }
 
  private:
   // The type of the host.
   HostType type_;
 
   // Similar to extension_id, host_id is a unique indentifier for a host,
   // e.g., an Extension or WebUI.
   std::string id_;
 };
 
+// An interface for all kinds of hosts who own user scripts.
+class Host {

[Devlin, 2015/02/09 17:40:24]

Can't this also be moved to renderer?  And just put kDefaultInstanceId in HostId
or something?

[Devlin, 2015/02/09 17:40:24]

Having a class named "Host" in the global namespace seems... a bit wrong.  In
the long run, we may want a namespace like "script_injection", but in the
short-term, we should probably just have this be ScriptInjectionHost or
InjectionHost (probably the latter, for brevity).  Also, since everything else
is in the extensions namespace for the time being, this probably should be, too.

[Xi Han, 2015/02/09 23:28:11]

That is true, I will rename it as InjectionHost.
I would still want to avoid namespace extensions, since this interface is
introduced to decouple extension from the code. 

[Xi Han, 2015/02/09 23:28:11]

Moved to renderer. Just put kDefaultInstanceId in HostId for now, and will move
it to ConsumerInstanceID later.

+ public:
+  // The default id of the instance that host will inject the script.
+  // If the instance is a regular tab, the |instance_id| is 0; if the instance
+  // is <webview>, the |instance_id| is a unique number that is bigger than 0.
+  static const int kDefaultInstanceId;
+
+  Host(const HostID& host_id);
+  virtual ~Host();
+
+  virtual const std::string& GetContentSecurityPolicy() const = 0;
+
+  // The base url for the host.
+  virtual const GURL& url() const = 0;
+
+  // The human-readable name of the host.
+  virtual const std::string name() const = 0;
+
+  // Returns true if the script should execute.
+  virtual extensions::PermissionsData::AccessType CanExecuteOnFrame(
+      const GURL& document_url,
+      const GURL& top_frame_url,
+      int tab_id,
+      bool is_declarative) const = 0;
+
+  const HostID& id() const { return id_; }
+ private:
+  // The ID of the host.
+  HostID id_;
+
+  DISALLOW_COPY_AND_ASSIGN(Host);
+};
+
 #endif  // EXTENSIONS_COMMON_HOST_ID_H_