Factor the extension loading code out of AccessibilityManager

chrome/browser/chromeos/accessibility/accessibility_manager.cc

Index: chrome/browser/chromeos/accessibility/accessibility_manager.cc
diff --git a/chrome/browser/chromeos/accessibility/accessibility_manager.cc b/chrome/browser/chromeos/accessibility/accessibility_manager.cc
index c82e76c523d44ddaa2866f3ad5dc2e4f0dc5aedc..49cdc72d765062f4d30e40c5dc60106d24b3f5fe 100644
--- a/chrome/browser/chromeos/accessibility/accessibility_manager.cc
+++ b/chrome/browser/chromeos/accessibility/accessibility_manager.cc
@@ -34,24 +34,19 @@
 #include "chrome/browser/accessibility/accessibility_extension_api.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/chromeos/accessibility/accessibility_extension_loader.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_highlight_manager.h"
 #include "chrome/browser/chromeos/accessibility/magnification_manager.h"
-#include "chrome/browser/chromeos/login/lock/screen_locker.h"
-#include "chrome/browser/chromeos/login/ui/login_display_host.h"
-#include "chrome/browser/chromeos/login/ui/webui_login_view.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/chromeos/ui/accessibility_focus_ring_controller.h"
 #include "chrome/browser/extensions/api/braille_display_private/stub_braille_controller.h"
-#include "chrome/browser/extensions/component_loader.h"
 #include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/extensions/tab_helper.h"
 #include "chrome/browser/prefs/incognito_mode_prefs.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/api/accessibility_private.h"
 #include "chrome/common/extensions/extension_constants.h"
-#include "chrome/common/extensions/manifest_handlers/content_scripts_handler.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/grit/browser_resources.h"
 #include "chromeos/audio/audio_a11y_controller.h"
@@ -65,17 +60,12 @@
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_source.h"
-#include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
-#include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/common/content_switches.h"
 #include "extensions/browser/event_router.h"
-#include "extensions/browser/extension_api_frame_id_map.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
-#include "extensions/browser/file_reader.h"
-#include "extensions/browser/script_executor.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/extension_resource.h"
@@ -119,182 +109,6 @@ BrailleController* GetBrailleController() {
   return BrailleController::GetInstance();
 }
 
-base::FilePath GetChromeVoxPath() {
-  base::FilePath path;
-  if (!PathService::Get(chrome::DIR_RESOURCES, &path))
-    NOTREACHED();
-  path = path.Append(extension_misc::kChromeVoxExtensionPath);
-  return path;
-}
-
-// Uses the ScriptExecutor associated with the given |render_view_host| to
-// execute the given |code|.
-void ExecuteScriptHelper(
-    content::RenderViewHost* render_view_host,
-    const std::string& code,
-    const std::string& extension_id) {
-  content::WebContents* web_contents =
-      content::WebContents::FromRenderViewHost(render_view_host);
-  if (!web_contents)
-    return;
-  if (!extensions::TabHelper::FromWebContents(web_contents))
-    extensions::TabHelper::CreateForWebContents(web_contents);
-  extensions::TabHelper::FromWebContents(web_contents)
-      ->script_executor()
-      ->ExecuteScript(HostID(HostID::EXTENSIONS, extension_id),
-                      extensions::ScriptExecutor::JAVASCRIPT, code,
-                      extensions::ScriptExecutor::INCLUDE_SUB_FRAMES,
-                      extensions::ExtensionApiFrameIdMap::kTopFrameId,
-                      extensions::ScriptExecutor::DONT_MATCH_ABOUT_BLANK,
-                      extensions::UserScript::DOCUMENT_IDLE,
-                      extensions::ScriptExecutor::ISOLATED_WORLD,
-                      extensions::ScriptExecutor::DEFAULT_PROCESS,
-                      GURL(),  // No webview src.
-                      GURL(),  // No file url.
-                      false,   // Not user gesture.
-                      extensions::ScriptExecutor::NO_RESULT,
-                      extensions::ScriptExecutor::ExecuteScriptCallback());
-}
-
-// Helper class that directly loads an extension's content scripts into
-// all of the frames corresponding to a given RenderViewHost.
-class ContentScriptLoader {
- public:
-  // Initialize the ContentScriptLoader with the ID of the extension
-  // and the RenderViewHost where the scripts should be loaded.
-  ContentScriptLoader(const std::string& extension_id,
-                      int render_process_id,
-                      int render_view_id)
-      : extension_id_(extension_id),
-        render_process_id_(render_process_id),
-        render_view_id_(render_view_id) {}
-
-  // Call this once with the ExtensionResource corresponding to each
-  // content script to be loaded.
-  void AppendScript(extensions::ExtensionResource resource) {
-    resources_.push(resource);
-  }
-
-  // Finally, call this method once to fetch all of the resources and
-  // load them. This method will delete this object when done.
-  void Run() {
-    if (resources_.empty()) {
-      delete this;
-      return;
-    }
-
-    extensions::ExtensionResource resource = resources_.front();
-    resources_.pop();
-    scoped_refptr<FileReader> reader(new FileReader(resource, base::Bind(
-        &ContentScriptLoader::OnFileLoaded, base::Unretained(this))));
-    reader->Start();
-  }
-
- private:
-  void OnFileLoaded(bool success, std::unique_ptr<std::string> data) {
-    if (success) {
-      RenderViewHost* render_view_host =
-          RenderViewHost::FromID(render_process_id_, render_view_id_);
-      if (render_view_host)
-        ExecuteScriptHelper(render_view_host, *data, extension_id_);
-    }
-    Run();
-  }
-
-  std::string extension_id_;
-  int render_process_id_;
-  int render_view_id_;
-  std::queue<extensions::ExtensionResource> resources_;
-};
-
-void InjectChromeVoxContentScript(
-    ExtensionService* extension_service,
-    int render_process_id,
-    int render_view_id,
-    const base::Closure& done_cb);
-
-void AddChromeVoxExtensionToComponentLoader(
-    extensions::ComponentLoader* component_loader,
-    base::Closure done_cb) {
-  component_loader->AddComponentFromDir(
-      GetChromeVoxPath(), extension_misc::kChromeVoxExtensionId, done_cb);
-}
-
-void LoadChromeVoxExtension(
-    Profile* profile,
-    RenderViewHost* render_view_host,
-    base::Closure done_cb) {
-  ExtensionService* extension_service =
-      extensions::ExtensionSystem::Get(profile)->extension_service();
-  if (render_view_host) {
-    // Wrap the passed in callback to inject the content script.
-    done_cb = base::Bind(
-        &InjectChromeVoxContentScript,
-        extension_service,
-        render_view_host->GetProcess()->GetID(),
-        render_view_host->GetRoutingID(),
-        done_cb);
-  }
-
-  AddChromeVoxExtensionToComponentLoader(extension_service->component_loader(),
-                                         done_cb);
-}
-
-void InjectChromeVoxContentScript(
-    ExtensionService* extension_service,
-    int render_process_id,
-    int render_view_id,
-    const base::Closure& done_cb) {
-  // Make sure to always run |done_cb|.  ChromeVox was loaded even if we end up
-  // not injecting into this particular render view.
-  base::ScopedClosureRunner done_runner(done_cb);
-  RenderViewHost* render_view_host =
-      RenderViewHost::FromID(render_process_id, render_view_id);
-  if (!render_view_host)
-    return;
-  const content::WebContents* web_contents =
-      content::WebContents::FromRenderViewHost(render_view_host);
-  GURL content_url;
-  if (web_contents)
-    content_url = web_contents->GetLastCommittedURL();
-  const extensions::Extension* extension =
-      extensions::ExtensionRegistry::Get(extension_service->profile())
-          ->enabled_extensions()
-          .GetByID(extension_misc::kChromeVoxExtensionId);
-
-  // Set a flag to tell ChromeVox that it's just been enabled,
-  // so that it won't interrupt our speech feedback enabled message.
-  ExecuteScriptHelper(render_view_host, "window.INJECTED_AFTER_LOAD = true;",
-                      extension->id());
-
-  // Inject ChromeVox' content scripts.
-  ContentScriptLoader* loader = new ContentScriptLoader(
-      extension->id(), render_view_host->GetProcess()->GetID(),
-      render_view_host->GetRoutingID());
-
-  const extensions::UserScriptList& content_scripts =
-      extensions::ContentScriptsInfo::GetContentScripts(extension);
-  for (const std::unique_ptr<extensions::UserScript>& script :
-       content_scripts) {
-    if (web_contents && !script->MatchesURL(content_url))
-      continue;
-    for (const std::unique_ptr<extensions::UserScript::File>& file :
-         script->js_scripts()) {
-      extensions::ExtensionResource resource =
-          extension->GetResource(file->relative_path());
-      loader->AppendScript(resource);
-    }
-  }
-  loader->Run();  // It cleans itself up when done.
-}
-
-void UnloadChromeVoxExtension(Profile* profile) {
-  base::FilePath path = GetChromeVoxPath();
-  ExtensionService* extension_service =
-      extensions::ExtensionSystem::Get(profile)->extension_service();
-  extension_service->component_loader()->Remove(path);
-}
-
 }  // namespace
 
 class ChromeVoxPanelWidgetObserver : public views::WidgetObserver {
@@ -409,8 +223,6 @@ AccessibilityManager* AccessibilityManager::Get() {
 
 AccessibilityManager::AccessibilityManager()
     : profile_(NULL),
-      chrome_vox_loaded_on_lock_screen_(false),
-      chrome_vox_loaded_on_user_screen_(false),
       large_cursor_pref_handler_(prefs::kAccessibilityLargeCursorEnabled),
       spoken_feedback_pref_handler_(prefs::kAccessibilitySpokenFeedbackEnabled),
       high_contrast_pref_handler_(prefs::kAccessibilityHighContrastEnabled),
@@ -478,6 +290,13 @@ AccessibilityManager::AccessibilityManager()
                       bundle.GetRawDataResource(IDR_SOUND_EXIT_SCREEN_WAV));
   manager->Initialize(SOUND_ENTER_SCREEN,
                       bundle.GetRawDataResource(IDR_SOUND_ENTER_SCREEN_WAV));
+
+  base::FilePath resources_path;
+  if (!PathService::Get(chrome::DIR_RESOURCES, &resources_path))
+    NOTREACHED();
+  chromevox_loader_ = base::WrapUnique(new AccessibilityExtensionLoader(
+      extension_misc::kChromeVoxExtensionId,
+      resources_path.Append(extension_misc::kChromeVoxExtensionPath)));
 }
 
 AccessibilityManager::~AccessibilityManager() {
@@ -622,17 +441,6 @@ void AccessibilityManager::UpdateSpokenFeedbackFromPref() {
 
   const bool enabled = profile_->GetPrefs()->GetBoolean(
       prefs::kAccessibilitySpokenFeedbackEnabled);
-
-  // If ChromeVox was already enabled, but not for this profile,
-  // add it to this profile.
-  auto* extension_service =
-      extensions::ExtensionSystem::Get(profile_)->extension_service();
-  auto* component_loader = extension_service->component_loader();
-  bool is_already_loaded =
-      component_loader->Exists(extension_misc::kChromeVoxExtensionId);
-  if (spoken_feedback_enabled_ && enabled && !is_already_loaded)
-    AddChromeVoxExtensionToComponentLoader(component_loader, base::Closure());
-
   if (spoken_feedback_enabled_ == enabled)
     return;
 
@@ -646,9 +454,12 @@ void AccessibilityManager::UpdateSpokenFeedbackFromPref() {
   NotifyAccessibilityStatusChanged(details);
 
   if (enabled) {
-    LoadChromeVox();
+    chromevox_loader_->Load(profile_, "window.INJECTED_AFTER_LOAD = true;",
+                            base::Bind(&AccessibilityManager::PostLoadChromeVox,
+                                       weak_ptr_factory_.GetWeakPtr()));
+

[David Tseng, 2016/09/08 21:18:42]

Remove

[dmazzoni, 2016/09/13 23:03:19]

Done

   } else {
-    UnloadChromeVox();
+    chromevox_loader_->Unload();
   }
   UpdateBrailleImeState();
 
@@ -656,93 +467,6 @@ void AccessibilityManager::UpdateSpokenFeedbackFromPref() {
   UpdateFocusHighlightFromPref();
 }
 
-void AccessibilityManager::LoadChromeVox() {
-  base::Closure done_cb = base::Bind(&AccessibilityManager::PostLoadChromeVox,
-                                     weak_ptr_factory_.GetWeakPtr(),
-                                     profile_);
-  ScreenLocker* screen_locker = ScreenLocker::default_screen_locker();
-  if (screen_locker && screen_locker->locked()) {
-    // If on the lock screen, loads ChromeVox only to the lock screen as for
-    // now. On unlock, it will be loaded to the user screen.
-    // (see. AccessibilityManager::Observe())
-    LoadChromeVoxToLockScreen(done_cb);
-  } else {
-    LoadChromeVoxToUserScreen(done_cb);
-  }
-}
-
-void AccessibilityManager::LoadChromeVoxToUserScreen(
-    const base::Closure& done_cb) {
-  if (chrome_vox_loaded_on_user_screen_)
-    return;
-
-  // Determine whether an OOBE screen is currently being shown. If so,
-  // ChromeVox will be injected directly into that screen.
-  content::WebUI* login_web_ui = NULL;
-
-  if (ProfileHelper::IsSigninProfile(profile_)) {
-    LoginDisplayHost* login_display_host = LoginDisplayHost::default_host();
-    if (login_display_host) {
-      WebUILoginView* web_ui_login_view =
-          login_display_host->GetWebUILoginView();
-      if (web_ui_login_view)
-        login_web_ui = web_ui_login_view->GetWebUI();
-    }
-
-    // Lock screen uses the signin progile.
-    chrome_vox_loaded_on_lock_screen_ = true;
-  }
-
-  chrome_vox_loaded_on_user_screen_ = true;
-  LoadChromeVoxExtension(
-      profile_, login_web_ui ?
-      login_web_ui->GetWebContents()->GetRenderViewHost() : NULL,
-      done_cb);
-}
-
-void AccessibilityManager::LoadChromeVoxToLockScreen(
-    const base::Closure& done_cb) {
-  if (chrome_vox_loaded_on_lock_screen_)
-    return;
-
-  ScreenLocker* screen_locker = ScreenLocker::default_screen_locker();
-  if (screen_locker && screen_locker->locked()) {
-    content::WebUI* lock_web_ui = screen_locker->GetAssociatedWebUI();
-    if (lock_web_ui) {
-      Profile* profile = Profile::FromWebUI(lock_web_ui);
-      chrome_vox_loaded_on_lock_screen_ = true;
-      LoadChromeVoxExtension(
-          profile,
-          lock_web_ui->GetWebContents()->GetRenderViewHost(),
-          done_cb);
-    }
-  }
-}
-
-void AccessibilityManager::UnloadChromeVox() {
-  if (chromevox_panel_) {
-    chromevox_panel_->Close();
-    chromevox_panel_ = nullptr;
-  }
-
-  if (chrome_vox_loaded_on_lock_screen_)
-    UnloadChromeVoxFromLockScreen();
-
-  if (chrome_vox_loaded_on_user_screen_) {
-    UnloadChromeVoxExtension(profile_);
-    chrome_vox_loaded_on_user_screen_ = false;
-  }
-
-  PostUnloadChromeVox(profile_);
-}
-
-void AccessibilityManager::UnloadChromeVoxFromLockScreen() {
-  // Lock screen uses the signin progile.
-  Profile* signin_profile = ProfileHelper::GetSigninProfile();
-  UnloadChromeVoxExtension(signin_profile);
-  chrome_vox_loaded_on_lock_screen_ = false;
-}
-
 bool AccessibilityManager::IsSpokenFeedbackEnabled() {
   return spoken_feedback_enabled_;
 }
@@ -1264,6 +988,13 @@ void AccessibilityManager::SetProfile(Profile* profile) {
         base::Bind(
             &AccessibilityManager::UpdateChromeOSAccessibilityHistograms,
             base::Unretained(this)));
+
+    chromevox_loader_->SetProfile(profile);
+
+    extensions::ExtensionRegistry* registry =
+        extensions::ExtensionRegistry::Get(profile);
+    if (!extension_registry_observer_.IsObserving(registry))
+      extension_registry_observer_.Add(registry);
   }
 
   large_cursor_pref_handler_.HandleProfileChanged(profile_, profile);
@@ -1344,7 +1075,7 @@ base::TimeDelta AccessibilityManager::PlayShutdownSound() {
 }
 
 void AccessibilityManager::InjectChromeVox(RenderViewHost* render_view_host) {
-  LoadChromeVoxExtension(profile_, render_view_host, base::Closure());
+  chromevox_loader_->InjectContentScript(render_view_host);

[David Tseng, 2016/09/08 20:39:31]

This doesn't look equivalent.

[dmazzoni, 2016/09/08 21:00:55]

You're right, but I think it was doing extra unnecessary work
before. The only place this was called was from
ChromeWebViewGuestDelegate, where it only called it if
AccessibilityManager::IsSpokenFeedbackEnabled() returned
true. So all it needs to do (and all that it ought to do
given what it's named) is inject the content script.
Adding the component extension again is redundant.

[David Tseng, 2016/09/08 21:18:42]

Same comment here -- if you're sure, then that's fine; otherwise, keep the
mechanical nature of this change and do this chaneg (along with the other
change) in a followup. Thanks!

[dmazzoni, 2016/09/13 23:03:19]

Makes sense.

Done.

 }
 
 std::unique_ptr<AccessibilityStatusSubscription>
@@ -1444,12 +1175,12 @@ void AccessibilityManager::Observe(
       bool is_screen_locked = *content::Details<bool>(details).ptr();
       if (spoken_feedback_enabled_) {
         if (is_screen_locked)
-          LoadChromeVoxToLockScreen(base::Closure());
+          chromevox_loader_->LoadToLockScreen(base::Closure());
         // If spoken feedback was enabled, make sure it is also enabled on
         // the user screen.
         // The status tray gets verbalized by user screen ChromeVox, so we need
         // to load it on the user screen even if the screen is locked.
-        LoadChromeVoxToUserScreen(base::Closure());
+        chromevox_loader_->LoadToUserScreen(base::Closure());
       }
       break;
     }
@@ -1489,8 +1220,20 @@ void AccessibilityManager::OnExtensionUnloaded(
   if (extension->id() == keyboard_listener_extension_id_) {
     keyboard_listener_extension_id_ = std::string();
     keyboard_listener_capture_ = false;
-    extension_registry_observer_.Remove(
-        extensions::ExtensionRegistry::Get(browser_context));
+  }
+
+  if (extension->id() == extension_misc::kChromeVoxExtensionId) {
+    // Do any teardown work needed immediately after ChromeVox actually unloads.
+    PlayEarcon(SOUND_SPOKEN_FEEDBACK_DISABLED, PlaySoundOption::ALWAYS);
+    // Clear the accessibility focus ring.
+    AccessibilityFocusRingController::GetInstance()->SetFocusRing(
+        std::vector<gfx::Rect>(),
+        AccessibilityFocusRingController::PERSIST_FOCUS_RING);
+
+    if (chromevox_panel_) {
+      chromevox_panel_->Close();
+      chromevox_panel_ = nullptr;
+    }
   }
 }
 
@@ -1498,14 +1241,14 @@ void AccessibilityManager::OnShutdown(extensions::ExtensionRegistry* registry) {
   extension_registry_observer_.Remove(registry);
 }
 
-void AccessibilityManager::PostLoadChromeVox(Profile* profile) {
+void AccessibilityManager::PostLoadChromeVox() {
   // Do any setup work needed immediately after ChromeVox actually loads.
   PlayEarcon(SOUND_SPOKEN_FEEDBACK_ENABLED, PlaySoundOption::ALWAYS);
 
-  if (chrome_vox_loaded_on_lock_screen_ ||
+  if (chromevox_loader_->loaded_on_lock_screen() ||
       should_speak_chrome_vox_announcements_on_user_screen_) {
     extensions::EventRouter* event_router =
-        extensions::EventRouter::Get(profile);
+        extensions::EventRouter::Get(profile_);
     CHECK(event_router);
 
     std::unique_ptr<base::ListValue> event_args(new base::ListValue());
@@ -1519,7 +1262,7 @@ void AccessibilityManager::PostLoadChromeVox(Profile* profile) {
   }
 
   should_speak_chrome_vox_announcements_on_user_screen_ =
-      chrome_vox_loaded_on_lock_screen_;
+      chromevox_loader_->loaded_on_lock_screen();
 
   if (!chromevox_panel_) {
     chromevox_panel_ = new ChromeVoxPanel(profile_);
@@ -1528,15 +1271,6 @@ void AccessibilityManager::PostLoadChromeVox(Profile* profile) {
   }
 }
 
-void AccessibilityManager::PostUnloadChromeVox(Profile* profile) {
-  // Do any teardown work needed immediately after ChromeVox actually unloads.
-  PlayEarcon(SOUND_SPOKEN_FEEDBACK_DISABLED, PlaySoundOption::ALWAYS);
-  // Clear the accessibility focus ring.
-  AccessibilityFocusRingController::GetInstance()->SetFocusRing(
-      std::vector<gfx::Rect>(),
-      AccessibilityFocusRingController::PERSIST_FOCUS_RING);
-}
-
 void AccessibilityManager::OnChromeVoxPanelClosing() {
   aura::Window* root_window = chromevox_panel_->GetRootWindow();
   chromevox_panel_widget_observer_.reset(nullptr);