Move V4L2 code into a webcam helper class.

extensions/browser/api/webcam_private/webcam_private_api.h

Index: extensions/browser/api/webcam_private/webcam_private_api.h
diff --git a/extensions/browser/api/webcam_private/webcam_private_api.h b/extensions/browser/api/webcam_private/webcam_private_api.h
index c4cef378e7ddbcecdd9d31db05837953cbd80b57..3c64e6c89edb24d3d06d2e55de279278bad41d17 100644
--- a/extensions/browser/api/webcam_private/webcam_private_api.h
+++ b/extensions/browser/api/webcam_private/webcam_private_api.h
@@ -5,12 +5,65 @@
 #ifndef EXTENSIONS_BROWSER_API_WEBCAM_PRIVATE_WEBCAM_PRIVATE_API_H_
 #define EXTENSIONS_BROWSER_API_WEBCAM_PRIVATE_WEBCAM_PRIVATE_API_H_
 
+#include <map>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/scoped_observer.h"
+#include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/extension_function.h"
+#include "extensions/browser/process_manager_observer.h"
 
 class Profile;
 
 namespace extensions {
 
+class ProcessManager;
+class Webcam;
+
+class WebcamPrivateAPI : public BrowserContextKeyedAPI,
+                         public ProcessManagerObserver {
+ public:
+  static BrowserContextKeyedAPIFactory<WebcamPrivateAPI>* GetFactoryInstance();
+
+  // Convenience method to get the WebcamPrivateAPI for a BrowserContext.
+  static WebcamPrivateAPI* Get(content::BrowserContext* context);
+
+  explicit WebcamPrivateAPI(content::BrowserContext* context);
+  ~WebcamPrivateAPI() override;
+
+  Webcam* GetWebcam(const std::string& extension_id,
+                    const std::string& webcam_id);
+
+ private:
+  friend class BrowserContextKeyedAPIFactory<WebcamPrivateAPI>;
+
+  bool GetDeviceId(const std::string& extension_id,
+                   const std::string& webcam_id,
+                   std::string* device_id);
+
+  // ProcessManagerObserver:
+  void OnBackgroundHostClose(const std::string& extension_id) override;
+
+  // BrowserContextKeyedAPI:
+  static const char* service_name() {
+    return "WebcamPrivateAPI";
+  }
+  static const bool kServiceIsNULLWhileTesting = true;
+  static const bool kServiceRedirectedInIncognito = true;
+
+  content::BrowserContext* const browser_context_;
+  ScopedObserver<ProcessManager, ProcessManagerObserver>
+      process_manager_observer_;
+
+  std::map<std::string, linked_ptr<Webcam>> webcams_;
+
+  base::WeakPtrFactory<WebcamPrivateAPI> weak_ptr_factory_;
+};
+
+template <>
+void BrowserContextKeyedAPIFactory<WebcamPrivateAPI>
+    ::DeclareFactoryDependencies();
+
 class WebcamPrivateSetFunction : public SyncExtensionFunction {
  public:
   WebcamPrivateSetFunction();