Move ExtensionService::GetExtensionById() to ExtensionRegistry

extensions/browser/extension_registry.h

Index: extensions/browser/extension_registry.h
diff --git a/extensions/browser/extension_registry.h b/extensions/browser/extension_registry.h
index aedd11a434f8866ca2730c8cdbdc8a8e0e7968c5..d878e61e84db8ec44e56741cad14925dd997c038 100644
--- a/extensions/browser/extension_registry.h
+++ b/extensions/browser/extension_registry.h
@@ -24,6 +24,16 @@ class Extension;
 // share a single registry.
 class ExtensionRegistry : public BrowserContextKeyedService {
  public:
+  // Flags to pass to GetExtensionById() to select which sets to look in.
+  enum IncludeFlag {
+    NONE        = 0,
+    ENABLED     = 1 << 0,
+    DISABLED    = 1 << 1,
+    TERMINATED  = 1 << 2,
+    BLACKLISTED = 1 << 3,
+    EVERYTHING = (1 << 4) - 1,
+  };
+
   ExtensionRegistry();
   virtual ~ExtensionRegistry();
 
@@ -45,6 +55,15 @@ class ExtensionRegistry : public BrowserContextKeyedService {
     return blacklisted_extensions_;
   }
 
+  // Find an extension by ID using |include_mask| to pick the sets to search:
+  //  * enabled_extensions()     --> ExtensionRegistry::ENABLED
+  //  * disabled_extensions()    --> ExtensionRegistry::DISABLED
+  //  * terminated_extensions()  --> ExtensionRegistry::TERMINATED
+  //  * blacklisted_extensions() --> ExtensionRegistry::BLACKLISTED
+  // Returns NULL if the extension is not found in the selected sets.
+  const Extension* GetExtensionById(const std::string& id,
+                                    int include_mask) const;
+
   // Adds the specified extension to the enabled set. The registry becomes an
   // owner. Any previous extension with the same ID is removed.
   // Returns true if there is no previous extension.