extensions/browser/extension_host.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef EXTENSIONS_BROWSER_EXTENSION_HOST_H_
   6 #define EXTENSIONS_BROWSER_EXTENSION_HOST_H_
   7
   8 #include <set>
   9 #include <string>
  10
  11 #include "base/logging.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/observer_list.h"
  14 #include "base/timer/elapsed_timer.h"
  15 #include "content/public/browser/web_contents_delegate.h"
  16 #include "content/public/browser/web_contents_observer.h"
  17 #include "extensions/browser/deferred_start_render_host.h"
  18 #include "extensions/browser/extension_function_dispatcher.h"
  19 #include "extensions/browser/extension_registry_observer.h"
  20 #include "extensions/common/stack_frame.h"
  21 #include "extensions/common/view_type.h"
  22
  23 class PrefsTabHelper;
  24
  25 namespace content {
  26 class BrowserContext;
  27 class RenderProcessHost;
  28 class RenderWidgetHostView;
  29 class SiteInstance;
  30 }
  31
  32 namespace extensions {
  33 class Extension;
  34 class ExtensionHostDelegate;
  35 class ExtensionHostObserver;
  36 class ExtensionHostQueue;
  37 class WindowController;
  38
  39 // This class is the browser component of an extension component's RenderView.
  40 // It handles setting up the renderer process, if needed, with special
  41 // privileges available to extensions.  It may have a view to be shown in the
  42 // browser UI, or it may be hidden.
  43 //
  44 // If you are adding code that only affects visible extension views (and not
  45 // invisible background pages) you should add it to ExtensionViewHost.
  46 class ExtensionHost : public DeferredStartRenderHost,
  47                       public content::WebContentsDelegate,
  48                       public content::WebContentsObserver,
  49                       public ExtensionFunctionDispatcher::Delegate,
  50                       public ExtensionRegistryObserver {
  51  public:
  52   ExtensionHost(const Extension* extension,
  53                 content::SiteInstance* site_instance,
  54                 const GURL& url, ViewType host_type);
  55   ~ExtensionHost() override;
  56
  57   const Extension* extension() const { return extension_; }
  58   const std::string& extension_id() const { return extension_id_; }
  59   content::WebContents* host_contents() const { return host_contents_.get(); }
  60   content::RenderViewHost* render_view_host() const;
  61   content::RenderProcessHost* render_process_host() const;
  62   bool has_loaded_once() const { return has_loaded_once_; }
  63   const GURL& initial_url() const { return initial_url_; }
  64   bool document_element_available() const {
  65     return document_element_available_;
  66   }
  67
  68   content::BrowserContext* browser_context() { return browser_context_; }
  69
  70   ViewType extension_host_type() const { return extension_host_type_; }
  71   const GURL& GetURL() const;
  72
  73   // Returns true if the render view is initialized and didn't crash.
  74   bool IsRenderViewLive() const;
  75
  76   // Prepares to initializes our RenderViewHost by creating its RenderView and
  77   // navigating to this host's url. Uses host_view for the RenderViewHost's view
  78   // (can be NULL). This happens delayed to avoid locking the UI.
  79   void CreateRenderViewSoon();
  80
  81   // Closes this host (results in [possibly asynchronous] deletion).
  82   void Close();
  83
  84   // Typical observer interface.
  85   void AddObserver(ExtensionHostObserver* observer);
  86   void RemoveObserver(ExtensionHostObserver* observer);
  87
  88   // Called when an event is dispatched to the event page associated with this
  89   // ExtensionHost.
  90   void OnBackgroundEventDispatched(const std::string& event_name, int event_id);
  91
  92   // Called by the ProcessManager when a network request is started by the
  93   // extension corresponding to this ExtensionHost.
  94   void OnNetworkRequestStarted(uint64 request_id);
  95
  96   // Called by the ProcessManager when a previously started network request is
  97   // finished.
  98   void OnNetworkRequestDone(uint64 request_id);
  99
 100   // content::WebContentsObserver:
 101   bool OnMessageReceived(const IPC::Message& message) override;
 102   void RenderViewCreated(content::RenderViewHost* render_view_host) override;
 103   void RenderViewDeleted(content::RenderViewHost* render_view_host) override;
 104   void RenderViewReady() override;
 105   void RenderProcessGone(base::TerminationStatus status) override;
 106   void DocumentAvailableInMainFrame() override;
 107   void DidStartLoading() override;
 108   void DidStopLoading() override;
 109
 110   // content::WebContentsDelegate:
 111   content::JavaScriptDialogManager* GetJavaScriptDialogManager(
 112       content::WebContents* source) override;
 113   void AddNewContents(content::WebContents* source,
 114                       content::WebContents* new_contents,
 115                       WindowOpenDisposition disposition,
 116                       const gfx::Rect& initial_rect,
 117                       bool user_gesture,
 118                       bool* was_blocked) override;
 119   void CloseContents(content::WebContents* contents) override;
 120   void RequestMediaAccessPermission(
 121       content::WebContents* web_contents,
 122       const content::MediaStreamRequest& request,
 123       const content::MediaResponseCallback& callback) override;
 124   bool CheckMediaAccessPermission(content::WebContents* web_contents,
 125                                   const GURL& security_origin,
 126                                   content::MediaStreamType type) override;
 127   bool IsNeverVisible(content::WebContents* web_contents) override;
 128
 129   // ExtensionRegistryObserver:
 130   void OnExtensionUnloaded(content::BrowserContext* browser_context,
 131                            const Extension* extension,
 132                            UnloadedExtensionInfo::Reason reason) override;
 133
 134  protected:
 135   // Called each time this ExtensionHost completes a load finishes loading,
 136   // before any stop-loading notifications or observer methods are called.
 137   virtual void OnDidStopFirstLoad();
 138
 139   // Navigates to the initial page.
 140   virtual void LoadInitialURL();
 141
 142   // Returns true if we're hosting a background page.
 143   virtual bool IsBackgroundPage() const;
 144
 145  private:
 146   // DeferredStartRenderHost:
 147   void CreateRenderViewNow() override;
 148   void AddDeferredStartRenderHostObserver(
 149       DeferredStartRenderHostObserver* observer) override;
 150   void RemoveDeferredStartRenderHostObserver(
 151       DeferredStartRenderHostObserver* observer) override;
 152
 153   // Message handlers.
 154   void OnEventAck(int event_id);
 155   void OnIncrementLazyKeepaliveCount();
 156   void OnDecrementLazyKeepaliveCount();
 157
 158   // Records UMA for load events.
 159   void RecordStopLoadingUMA();
 160
 161   // Delegate for functionality that cannot exist in the extensions module.
 162   scoped_ptr<ExtensionHostDelegate> delegate_;
 163
 164   // The extension that we're hosting in this view.
 165   const Extension* extension_;
 166
 167   // Id of extension that we're hosting in this view.
 168   const std::string extension_id_;
 169
 170   // The browser context that this host is tied to.
 171   content::BrowserContext* browser_context_;
 172
 173   // The host for our HTML content.
 174   scoped_ptr<content::WebContents> host_contents_;
 175
 176   // A weak pointer to the current or pending RenderViewHost. We don't access
 177   // this through the host_contents because we want to deal with the pending
 178   // host, so we can send messages to it before it finishes loading.
 179   content::RenderViewHost* render_view_host_;
 180
 181   // Whether the ExtensionHost has finished loading some content at least once.
 182   // There may be subsequent loads - such as reloads and navigations - and this
 183   // will not affect its value (it will remain true).
 184   bool has_loaded_once_;
 185
 186   // True if the main frame has finished parsing.
 187   bool document_element_available_;
 188
 189   // The original URL of the page being hosted.
 190   GURL initial_url_;
 191
 192   // Messages sent out to the renderer that have not been acknowledged yet.
 193   std::set<int> unacked_messages_;
 194
 195   // The type of view being hosted.
 196   ViewType extension_host_type_;
 197
 198   // Measures how long since the ExtensionHost object was created. This can be
 199   // used to measure the responsiveness of UI. For example, it's important to
 200   // keep this as low as possible for popups. Contrast this to |load_start_|,
 201   // for which a low value does not necessarily mean a responsive UI, as
 202   // ExtensionHosts may sit in an ExtensionHostQueue for a long time.
 203   base::ElapsedTimer create_start_;
 204
 205   // Measures how long since the initial URL started loading. This timer is
 206   // started only once the ExtensionHost has exited the ExtensionHostQueue.
 207   scoped_ptr<base::ElapsedTimer> load_start_;
 208
 209   base::ObserverList<ExtensionHostObserver> observer_list_;
 210   base::ObserverList<DeferredStartRenderHostObserver>
 211       deferred_start_render_host_observer_list_;
 212
 213   DISALLOW_COPY_AND_ASSIGN(ExtensionHost);
 214 };
 215
 216 }  // namespace extensions
 217
 218 #endif  // EXTENSIONS_BROWSER_EXTENSION_HOST_H_