Make it possible to load ChromeVox on the oobe and login screens.

BUG=chromium-os:14807
TEST=manual testing
Review URL: http://codereview.chromium.org/7550027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@95782 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/chromeos/accessibility_util.cc

@@ -4,21 +4,79 @@
 
 #include "chrome/browser/chromeos/accessibility_util.h"
 
+#include "base/callback.h"
 #include "base/logging.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_accessibility_api.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/file_reader.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/common/extensions/extension_messages.h"
+#include "chrome/common/extensions/extension_resource.h"
 #include "chrome/common/pref_names.h"
+#include "content/browser/webui/web_ui.h"
+#include "content/browser/renderer_host/render_view_host.h"
 #include "grit/browser_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace chromeos {
 namespace accessibility {
 
+// 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,
+                      RenderViewHost* render_view_host)
+      : extension_id_(extension_id),
+        render_view_host_(render_view_host) {}
 
-void EnableAccessibility(bool enabled) {
+  // Call this once with the ExtensionResource corresponding to each
+  // content script to be loaded.
+  void AppendScript(ExtensionResource resource) {
+    resources_.push(resource);
+  }
+
+  // Fianlly, 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;
+    }
+
+    ExtensionResource resource = resources_.front();
+    resources_.pop();
+    scoped_refptr<FileReader> reader(new FileReader(resource, NewCallback(
+        this, &ContentScriptLoader::OnFileLoaded)));
+    reader->Start();
+  }
+
+ private:
+  void OnFileLoaded(bool success, const std::string& data) {
+    if (success) {
+      ExtensionMsg_ExecuteCode_Params params;
+      params.request_id = 0;
+      params.extension_id = extension_id_;
+      params.is_javascript = true;
+      params.code = data;
+      params.all_frames = true;
+      params.in_main_world = false;
+      render_view_host_->Send(new ExtensionMsg_ExecuteCode(
+          render_view_host_->routing_id(), params));
+    }
+    Run();
+  }
+
+  std::string extension_id_;
+  RenderViewHost* render_view_host_;
+  std::queue<ExtensionResource> resources_;
+};
+
+void EnableAccessibility(bool enabled, WebUI* login_web_ui) {
   bool accessibility_enabled = g_browser_process &&
       g_browser_process->local_state()->GetBoolean(
           prefs::kAccessibilityEnabled);
@@ -44,7 +102,26 @@ void EnableAccessibility(bool enabled) {
   ExtensionService::ComponentExtensionInfo info(manifest, path);
   if (enabled) { // Load ChromeVox
     extension_service->register_component_extension(info);
-    extension_service->LoadComponentExtension(info);
+    const Extension* extension =
+        extension_service->LoadComponentExtension(info);
+
+    if (login_web_ui) {
+      RenderViewHost* render_view_host = login_web_ui->GetRenderViewHost();
+      ContentScriptLoader* loader = new ContentScriptLoader(
+          extension->id(), render_view_host);
+
+      for (size_t i = 0; i < extension->content_scripts().size(); i++) {
+        const UserScript& script = extension->content_scripts()[i];
+        for (size_t j = 0; j < script.js_scripts().size(); ++j) {
+          const UserScript::File &file = script.js_scripts()[j];
+          ExtensionResource resource = extension->GetResource(
+              file.relative_path());
+          loader->AppendScript(resource);
+        }
+      }
+      loader->Run();  // It cleans itself up when done.
+    }
+
     LOG(INFO) << "ChromeVox was Loaded.";
   } else { // Unload ChromeVox
     extension_service->UnloadComponentExtension(info);
@@ -53,12 +130,12 @@ void EnableAccessibility(bool enabled) {
   }
 }
 
-void ToggleAccessibility() {
+void ToggleAccessibility(WebUI* login_web_ui) {
   bool accessibility_enabled = g_browser_process &&
       g_browser_process->local_state()->GetBoolean(
           prefs::kAccessibilityEnabled);
   accessibility_enabled = !accessibility_enabled;
-  EnableAccessibility(accessibility_enabled);
+  EnableAccessibility(accessibility_enabled, login_web_ui);
 };
 
 }  // namespace accessibility

chrome/browser/chromeos/accessibility_util.h

@@ -6,11 +6,20 @@
 #define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_UTIL_H_
 #pragma once
 
+class WebUI;
+
 namespace chromeos {
 namespace accessibility {
 
-void EnableAccessibility(bool enabled);
-void ToggleAccessibility();
+// Enable or disable accessibility. Enabling accessibility installs the
+// ChromeVox component extension.  If this is being called in a login/oobe
+// login screen, pass the WebUI object in login_web_ui so that ChromeVox
+// can be injected directly into that screen, otherwise it should be NULL.
+void EnableAccessibility(bool enabled, WebUI* login_web_ui);
+
+// Toggles whether Chrome OS accessibility is on or off. See docs for
+// EnableAccessibility, above.
+void ToggleAccessibility(WebUI* login_web_ui);
 
 }  // namespace accessibility
 }  // namespace chromeos

chrome/browser/chromeos/login/webui_login_view.cc

@@ -68,7 +68,7 @@ std::string WebUILoginView::GetClassName() const {
 bool WebUILoginView::AcceleratorPressed(
     const views::Accelerator& accelerator) {
   if (accelerator == accel_toggle_accessibility_) {
-    accessibility::ToggleAccessibility();
+    accessibility::ToggleAccessibility(GetWebUI());
   } else {
     return false;
   }

chrome/browser/ui/webui/chromeos/login/core_oobe_handler.cc

@@ -60,7 +60,7 @@ void CoreOobeHandler::OnInitialized(const base::ListValue* args) {
 }
 
 void CoreOobeHandler::OnToggleAccessibility(const base::ListValue* args) {
-  accessibility::ToggleAccessibility();
+  accessibility::ToggleAccessibility(web_ui_);
 }
 
 void CoreOobeHandler::ShowOobeUI(bool show) {

chrome/browser/ui/webui/options/chromeos/system_options_handler.cc

@@ -105,5 +105,5 @@ void SystemOptionsHandler::AccessibilityChangeCallback(const ListValue* args) {
   args->GetString(0, &checked_str);
   bool accessibility_enabled = (checked_str == "true");
 
-  chromeos::accessibility::EnableAccessibility(accessibility_enabled);
+  chromeos::accessibility::EnableAccessibility(accessibility_enabled, NULL);
 }