Split ExtensionWebContentsObserver into base and Chrome implementations

This allows app_shell to use a simplified ExtensionWebContentsObserver while
Chrome maintains its more complex version.

* Move ExtensionWebContentsObserver to src/extensions
* Introduce ChromeExtensionWebContentsObserver
* Delegate out observer creation from ExtensionHost

Removing this dependency on Chrome will allow ExtensionHost to move into
src/extensions and break another app_shell -> Chrome dependency.

BUG=321341
TEST=browser_tests ErrorConsole* and Extension*
TBR=stevenjb@chromium.org for mechanical changes to chrome/browser/chromeos
TBR=msw@chromium.org for mechanical changes to chrome/browser/ui

Review URL: https://codereview.chromium.org/205243004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@258372 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 174 insertions, 0 deletions

diff --git a/extensions/browser/extension_web_contents_observer.cc b/extensions/browser/extension_web_contents_observer.cc
new file mode 100644
index 0000000..e64fff1
--- /dev/null
+++ b/extensions/browser/extension_web_contents_observer.cc
@@ -0,0 +1,111 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "extensions/browser/extension_web_contents_observer.h"
+
+#include "content/public/browser/child_process_security_policy.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/site_instance.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/common/url_constants.h"
+#include "extensions/browser/extension_prefs.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/browser/view_type_utils.h"
+#include "extensions/common/constants.h"
+#include "extensions/common/extension_messages.h"
+
+namespace extensions {
+
+ExtensionWebContentsObserver::ExtensionWebContentsObserver(
+    content::WebContents* web_contents)
+    : content::WebContentsObserver(web_contents),
+      browser_context_(web_contents->GetBrowserContext()) {}
+
+ExtensionWebContentsObserver::~ExtensionWebContentsObserver() {}
+
+void ExtensionWebContentsObserver::RenderViewCreated(
+    content::RenderViewHost* render_view_host) {
+  render_view_host->Send(new ExtensionMsg_NotifyRenderViewType(
+      render_view_host->GetRoutingID(), GetViewType(web_contents())));
+
+  const Extension* extension = GetExtension(render_view_host);
+  if (!extension)
+    return;
+
+  content::RenderProcessHost* process = render_view_host->GetProcess();
+
+  // Some extensions use chrome:// URLs.
+  // This is a temporary solution. Replace it with access to chrome-static://
+  // once it is implemented. See: crbug.com/226927.
+  Manifest::Type type = extension->GetType();
+  if (type == Manifest::TYPE_EXTENSION ||
+      type == Manifest::TYPE_LEGACY_PACKAGED_APP ||
+      (type == Manifest::TYPE_PLATFORM_APP &&
+       extension->location() == Manifest::COMPONENT)) {
+    content::ChildProcessSecurityPolicy::GetInstance()->GrantScheme(
+        process->GetID(), content::kChromeUIScheme);
+  }
+
+  // Some extensions use file:// URLs.
+  if (type == Manifest::TYPE_EXTENSION ||
+      type == Manifest::TYPE_LEGACY_PACKAGED_APP) {
+    ExtensionPrefs* prefs = ExtensionPrefs::Get(browser_context_);
+    if (prefs->AllowFileAccess(extension->id())) {
+      content::ChildProcessSecurityPolicy::GetInstance()->GrantScheme(
+          process->GetID(), content::kFileScheme);
+    }
+  }
+
+  switch (type) {
+    case Manifest::TYPE_EXTENSION:
+    case Manifest::TYPE_USER_SCRIPT:
+    case Manifest::TYPE_HOSTED_APP:
+    case Manifest::TYPE_LEGACY_PACKAGED_APP:
+    case Manifest::TYPE_PLATFORM_APP:
+      // Always send a Loaded message before ActivateExtension so that
+      // ExtensionDispatcher knows what Extension is active, not just its ID.
+      // This is important for classifying the Extension's JavaScript context
+      // correctly (see ExtensionDispatcher::ClassifyJavaScriptContext).
+      render_view_host->Send(
+          new ExtensionMsg_Loaded(std::vector<ExtensionMsg_Loaded_Params>(
+              1, ExtensionMsg_Loaded_Params(extension))));
+      render_view_host->Send(
+          new ExtensionMsg_ActivateExtension(extension->id()));
+      break;
+
+    case Manifest::TYPE_UNKNOWN:
+    case Manifest::TYPE_THEME:
+    case Manifest::TYPE_SHARED_MODULE:
+      break;
+  }
+}
+
+const Extension* ExtensionWebContentsObserver::GetExtension(
+    content::RenderViewHost* render_view_host) {
+  std::string extension_id = GetExtensionId(render_view_host);
+  if (extension_id.empty())
+    return NULL;
+
+  // May be null if the extension doesn't exist, for example if somebody typos
+  // a chrome-extension:// URL.
+  return ExtensionRegistry::Get(browser_context_)
+      ->GetExtensionById(extension_id, ExtensionRegistry::ENABLED);
+}
+
+// static
+std::string ExtensionWebContentsObserver::GetExtensionId(
+    content::RenderViewHost* render_view_host) {
+  // Note that due to ChromeContentBrowserClient::GetEffectiveURL(), hosted apps
+  // (excluding bookmark apps) will have a chrome-extension:// URL for their
+  // site, so we can ignore that wrinkle here.
+  const GURL& site = render_view_host->GetSiteInstance()->GetSiteURL();
+
+  if (!site.SchemeIs(kExtensionScheme))
+    return std::string();
+
+  return site.host();
+}
+
+}  // namespace extensions
diff --git a/extensions/browser/extension_web_contents_observer.h b/extensions/browser/extension_web_contents_observer.h
new file mode 100644
index 0000000..a366e43
--- /dev/null
+++ b/extensions/browser/extension_web_contents_observer.h
@@ -0,0 +1,61 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef EXTENSIONS_BROWSER_EXTENSION_WEB_CONTENTS_OBSERVER_H_
+#define EXTENSIONS_BROWSER_EXTENSION_WEB_CONTENTS_OBSERVER_H_
+
+#include <string>
+
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "content/public/browser/web_contents_observer.h"
+
+namespace content {
+class BrowserContext;
+class RenderViewHost;
+class WebContents;
+}
+
+namespace extensions {
+class Extension;
+
+// A web contents observer used for renderer and extension processes. Grants the
+// renderer access to certain URL scheme patterns for extensions and notifies
+// the renderer that the extension was loaded.
+//
+// Extension system embedders must create an instance for every extension
+// WebContents. It must be a subclass so that creating an instance via
+// content::WebContentsUserData::CreateForWebContents() provides an object of
+// the correct type. For an example, see ChromeExtensionWebContentsObserver.
+class ExtensionWebContentsObserver : public content::WebContentsObserver {
+ protected:
+  explicit ExtensionWebContentsObserver(content::WebContents* web_contents);
+  virtual ~ExtensionWebContentsObserver();
+
+  content::BrowserContext* browser_context() { return browser_context_; }
+
+  // content::WebContentsObserver overrides.
+
+  // A subclass should invoke this method to finish extension process setup.
+  virtual void RenderViewCreated(content::RenderViewHost* render_view_host)
+      OVERRIDE;
+
+  // Returns the extension or app associated with a render view host. Returns
+  // NULL if the render view host is not for a valid extension.
+  const Extension* GetExtension(content::RenderViewHost* render_view_host);
+
+  // Returns the extension or app ID associated with a render view host. Returns
+  // the empty string if the render view host is not for a valid extension.
+  static std::string GetExtensionId(content::RenderViewHost* render_view_host);
+
+ private:
+  // The BrowserContext associated with the WebContents being observed.
+  content::BrowserContext* browser_context_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionWebContentsObserver);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_EXTENSION_WEB_CONTENTS_OBSERVER_H_
diff --git a/extensions/extensions.gyp b/extensions/extensions.gyp
index 4abb2b3..bcccc7c 100644
--- a/extensions/extensions.gyp
+++ b/extensions/extensions.gyp
@@ -266,6 +266,8 @@
         'browser/extension_system.h',
         'browser/extension_system_provider.cc',
         'browser/extension_system_provider.h',
+        'browser/extension_web_contents_observer.cc',
+        'browser/extension_web_contents_observer.h',
         'browser/extensions_browser_client.cc',
         'browser/extensions_browser_client.h',
         'browser/external_provider_interface.h',