Move GuestView layer in browser to components

In addition to moving the browser-side of the GuestView layer into components, this CL also:

1. Replaces some loops to the top level web contents with GuestViewBase::GetTopLevelWebContents.
2. Installs the ExtensionsGuestViewMessageFilter in appshell.
3. Move some files out of extensions/common/guest_view to components/guest_view/common

BUG=444869

Review URL: https://codereview.chromium.org/1102173002

Cr-Commit-Position: refs/heads/master@{#328243}

33 files changed, 2837 insertions, 7 deletions

diff --git a/components/BUILD.gn b/components/BUILD.gn
index 66864f0..7821039 100644
--- a/components/BUILD.gn
+++ b/components/BUILD.gn
@@ -48,6 +48,7 @@ group("all_components") {
     "//components/feedback",
     "//components/gcm_driver",
     "//components/google/core/browser",
+    "//components/guest_view:guest_view",
     "//components/history/content/browser",
     "//components/history/core/browser",
     "//components/history/core/common",
diff --git a/components/components.gyp b/components/components.gyp
index f8dee130..b59e82c 100644
--- a/components/components.gyp
+++ b/components/components.gyp
@@ -30,6 +30,7 @@
     'favicon_base.gypi',
     'gcm_driver.gypi',
     'google.gypi',
+    'guest_view.gypi',
     'handoff.gypi',
     'history.gypi',
     'infobars.gypi',
diff --git a/components/components_tests.gyp b/components/components_tests.gyp
index 26ef376..2ee73c9 100644
--- a/components/components_tests.gyp
+++ b/components/components_tests.gyp
@@ -217,6 +217,9 @@
       'google/core/browser/google_url_tracker_unittest.cc',
       'google/core/browser/google_util_unittest.cc',
     ],
+    'guest_view_unittest_sources': [
+      'guest_view/browser/guest_view_manager_unittest.cc'
+    ],
     'history_unittest_sources': [
       'history/content/browser/content_history_backend_unittest.cc',
       'history/core/browser/android/android_history_types_unittest.cc',
@@ -755,6 +758,8 @@
         'components.gyp:gcm_driver',
         'components.gyp:gcm_driver_test_support',
         'components.gyp:google_core_browser',
+        'components.gyp:guest_view',
+        'components.gyp:guest_view_test_support',
         'components.gyp:history_core_browser',
         'components.gyp:history_core_common',
         'components.gyp:history_core_test_support',
@@ -844,6 +849,7 @@
           'sources': [
             '<@(devtools_http_handler_unittest_sources)',
             '<@(error_page_unittest_sources)',
+            '<@(guest_view_unittest_sources)',
             '<@(navigation_interception_unittest_sources)',
             '<@(network_hints_unittest_sources)',
             '<@(power_unittest_sources)',
diff --git a/components/constrained_window/BUILD.gn b/components/constrained_window/BUILD.gn
index cbbb36f..55aae21 100644
--- a/components/constrained_window/BUILD.gn
+++ b/components/constrained_window/BUILD.gn
@@ -10,6 +10,7 @@ static_library("constrained_window") {
   ]
 
   deps = [
+    "//components/guest_view:guest_view",
     "//components/web_modal",
     "//ui/views",
     "//skia",
diff --git a/components/constrained_window/DEPS b/components/constrained_window/DEPS
index 9f4c9d1..9ddd155 100644
--- a/components/constrained_window/DEPS
+++ b/components/constrained_window/DEPS
@@ -1,4 +1,5 @@
 include_rules = [
+  "+components/guest_view",
   "+components/web_modal",
   "+ui/base",
   "+ui/gfx",
diff --git a/components/constrained_window/constrained_window_views.cc b/components/constrained_window/constrained_window_views.cc
index 577ee03..2f3c3da 100644
--- a/components/constrained_window/constrained_window_views.cc
+++ b/components/constrained_window/constrained_window_views.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 
 #include "components/constrained_window/constrained_window_views_client.h"
+#include "components/guest_view/browser/guest_view_base.h"
 #include "components/web_modal/popup_manager.h"
 #include "components/web_modal/web_contents_modal_dialog_host.h"
 #include "ui/views/border.h"
@@ -134,8 +135,8 @@ views::Widget* ShowWebModalDialogViews(
   DCHECK(constrained_window_views_client);
   // For embedded WebContents, use the embedder's WebContents for constrained
   // window.
-  content::WebContents* web_contents = constrained_window_views_client->
-      GetEmbedderWebContents(initiator_web_contents);
+  content::WebContents* web_contents =
+      guest_view::GuestViewBase::GetTopLevelWebContents(initiator_web_contents);
   views::Widget* widget = CreateWebModalDialogViews(dialog, web_contents);
   web_modal::PopupManager* popup_manager =
       web_modal::PopupManager::FromWebContents(web_contents);
diff --git a/components/constrained_window/constrained_window_views_client.h b/components/constrained_window/constrained_window_views_client.h
index c5b1860..de58b2c 100644
--- a/components/constrained_window/constrained_window_views_client.h
+++ b/components/constrained_window/constrained_window_views_client.h
@@ -21,11 +21,6 @@ class ConstrainedWindowViewsClient {
  public:
   virtual ~ConstrainedWindowViewsClient() {}
 
-  // Returns the web contents that a constrained window should be modal to
-  // in the embedder's context.
-  virtual content::WebContents* GetEmbedderWebContents(
-      content::WebContents* initiator_web_contents) = 0;
-
   // Returns the modal window host for the |parent| native window.
   virtual web_modal::ModalDialogHost* GetModalDialogHost(
       gfx::NativeWindow parent) = 0;
diff --git a/components/guest_view.gypi b/components/guest_view.gypi
new file mode 100644
index 0000000..dbbddcc
--- /dev/null
+++ b/components/guest_view.gypi
@@ -0,0 +1,55 @@
+# Copyright 2015 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.
+{
+  'targets': [
+    {
+      'target_name': 'guest_view',
+      'type': 'static_library',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../content/content.gyp:content_browser',
+        '../content/content.gyp:content_common',
+      ],
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        'guest_view/browser/guest_view.h',
+        'guest_view/browser/guest_view_base.cc',
+        'guest_view/browser/guest_view_base.h',
+        'guest_view/browser/guest_view_event.cc',
+        'guest_view/browser/guest_view_event.h',
+        'guest_view/browser/guest_view_manager.cc',
+        'guest_view/browser/guest_view_manager.h',
+        'guest_view/browser/guest_view_manager_delegate.cc',
+        'guest_view/browser/guest_view_manager_delegate.h',
+        'guest_view/browser/guest_view_manager_factory.h',
+        'guest_view/browser/guest_view_message_filter.cc',
+        'guest_view/browser/guest_view_message_filter.h',
+        'guest_view/common/guest_view_constants.cc',
+        'guest_view/common/guest_view_constants.h',
+        'guest_view/common/guest_view_message_generator.cc',
+        'guest_view/common/guest_view_message_generator.h'
+        'guest_view/common/guest_view_messages.h',
+      ],
+    },
+    {
+      'target_name': 'guest_view_test_support',
+      'type': 'static_library',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../content/content.gyp:content_browser',
+        '../content/content.gyp:content_common',
+        '../content/content_shell_and_tests.gyp:test_support_content',
+      ],
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        'guest_view/browser/test_guest_view_manager.h',
+        'guest_view/browser/test_guest_view_manager.cc',
+      ],
+    }
+  ],
+}
diff --git a/components/guest_view/BUILD.gn b/components/guest_view/BUILD.gn
new file mode 100644
index 0000000..0beda18
--- /dev/null
+++ b/components/guest_view/BUILD.gn
@@ -0,0 +1,46 @@
+# Copyright 2015 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.
+
+static_library("guest_view") {
+  output_name = "guest_view"
+  sources = [
+    "//components/guest_view/browser/guest_view.h",
+    "//components/guest_view/browser/guest_view_base.cc",
+    "//components/guest_view/browser/guest_view_base.h",
+    "//components/guest_view/browser/guest_view_event.cc",
+    "//components/guest_view/browser/guest_view_event.h",
+    "//components/guest_view/browser/guest_view_manager.cc",
+    "//components/guest_view/browser/guest_view_manager.h",
+    "//components/guest_view/browser/guest_view_manager_delegate.cc",
+    "//components/guest_view/browser/guest_view_manager_delegate.h",
+    "//components/guest_view/browser/guest_view_manager_factory.h",
+    "//components/guest_view/browser/guest_view_message_filter.cc",
+    "//components/guest_view/browser/guest_view_message_filter.h",
+    "//components/guest_view/common/guest_view_constants.cc",
+    "//components/guest_view/common/guest_view_constants.h",
+    "//components/guest_view/common/guest_view_message_generator.cc",
+    "//components/guest_view/common/guest_view_message_generator.h",
+    "//components/guest_view/common/guest_view_messages.h",
+  ]
+
+  deps = [
+    "//base",
+    "//content/public/browser",
+    "//content/public/common",
+    "//third_party/WebKit/public:blink",
+  ]
+}
+
+static_library("test_support") {
+  testonly = true
+  sources = [
+    "//components/guest_view/browser/test_guest_view_manager.cc",
+    "//components/guest_view/browser/test_guest_view_manager.h",
+  ]
+
+  deps = [
+    ":guest_view",
+    "//content/test:test_support",
+  ]
+}
diff --git a/components/guest_view/OWNERS b/components/guest_view/OWNERS
new file mode 100644
index 0000000..f9575e8
--- /dev/null
+++ b/components/guest_view/OWNERS
@@ -0,0 +1,3 @@
+fsamuel@chromium.org
+lazyboy@chromium.org
+hanxi@chromium.org
diff --git a/components/guest_view/browser/DEPS b/components/guest_view/browser/DEPS
new file mode 100644
index 0000000..f0c51e4
--- /dev/null
+++ b/components/guest_view/browser/DEPS
@@ -0,0 +1,8 @@
+include_rules = [
+  "+components/ui/zoom",
+  "+content/public/browser",
+  "+content/public/common",
+  "+content/public/test",
+  "+ipc",
+  '+third_party/WebKit/public/web/WebInputEvent.h',
+]
diff --git a/components/guest_view/browser/guest_view.h b/components/guest_view/browser/guest_view.h
new file mode 100644
index 0000000..f99fe83
--- /dev/null
+++ b/components/guest_view/browser/guest_view.h
@@ -0,0 +1,70 @@
+// 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 COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_H_
+#define COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_H_
+
+#include "components/guest_view/browser/guest_view_base.h"
+#include "components/guest_view/browser/guest_view_manager.h"
+#include "content/public/browser/render_frame_host.h"
+
+namespace guest_view {
+
+// A GuestView is the templated base class for out-of-process frames in the
+// chrome layer. GuestView is templated on its derived type to allow for type-
+// safe access. See GuestViewBase for more information.
+template <typename T>
+class GuestView : public GuestViewBase {
+ public:
+  static T* From(int embedder_process_id, int guest_instance_id) {
+    auto guest = GuestViewBase::From(embedder_process_id, guest_instance_id);
+    if (!guest)
+      return nullptr;
+    return guest->As<T>();
+  }
+
+  static T* FromWebContents(const content::WebContents* contents) {
+    auto guest = GuestViewBase::FromWebContents(contents);
+    return guest ? guest->As<T>() : nullptr;
+  }
+
+  static T* FromFrameID(int render_process_id, int render_frame_id) {
+    auto render_frame_host =
+        content::RenderFrameHost::FromID(render_process_id, render_frame_id);
+    if (!render_frame_host)
+      return nullptr;
+
+    auto web_contents =
+        content::WebContents::FromRenderFrameHost(render_frame_host);
+    return FromWebContents(web_contents);
+  }
+
+  T* GetOpener() const {
+    GuestViewBase* guest = GuestViewBase::GetOpener();
+    if (!guest)
+      return nullptr;
+    return guest->As<T>();
+  }
+
+  void SetOpener(T* opener) {
+    GuestViewBase::SetOpener(opener);
+  }
+
+  // GuestViewBase implementation.
+  const char* GetViewType() const final {
+    return T::Type;
+  }
+
+ protected:
+  explicit GuestView(content::WebContents* owner_web_contents)
+      : GuestViewBase(owner_web_contents) {}
+  ~GuestView() override {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GuestView);
+};
+
+}  // namespace guest_view
+
+#endif  // COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_H_
diff --git a/components/guest_view/browser/guest_view_base.cc b/components/guest_view/browser/guest_view_base.cc
new file mode 100644
index 0000000..1b1b5ed
--- /dev/null
+++ b/components/guest_view/browser/guest_view_base.cc
@@ -0,0 +1,821 @@
+// 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 "components/guest_view/browser/guest_view_base.h"
+
+#include "base/lazy_instance.h"
+#include "base/strings/utf_string_conversions.h"
+#include "components/guest_view/browser/guest_view_event.h"
+#include "components/guest_view/browser/guest_view_manager.h"
+#include "components/guest_view/common/guest_view_constants.h"
+#include "components/guest_view/common/guest_view_messages.h"
+#include "components/ui/zoom/page_zoom.h"
+#include "components/ui/zoom/zoom_controller.h"
+#include "content/public/browser/navigation_details.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_widget_host_view.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/common/page_zoom.h"
+#include "content/public/common/url_constants.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+
+using content::WebContents;
+
+namespace content {
+struct FrameNavigateParams;
+}
+
+namespace guest_view {
+
+namespace {
+
+using WebContentsGuestViewMap = std::map<const WebContents*, GuestViewBase*>;
+static base::LazyInstance<WebContentsGuestViewMap> webcontents_guestview_map =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+SetSizeParams::SetSizeParams() {
+}
+SetSizeParams::~SetSizeParams() {
+}
+
+// This observer ensures that the GuestViewBase destroys itself when its
+// embedder goes away. It also tracks when the embedder's fullscreen is
+// toggled so the guest can change itself accordingly.
+class GuestViewBase::OwnerContentsObserver : public WebContentsObserver {
+ public:
+  OwnerContentsObserver(GuestViewBase* guest,
+                        content::WebContents* embedder_web_contents)
+      : WebContentsObserver(embedder_web_contents),
+        is_fullscreen_(false),
+        destroyed_(false),
+        guest_(guest) {}
+
+  ~OwnerContentsObserver() override {}
+
+  // WebContentsObserver implementation.
+  void WebContentsDestroyed() override {
+    // If the embedder is destroyed then destroy the guest.
+    Destroy();
+  }
+
+  void DidNavigateMainFrame(
+      const content::LoadCommittedDetails& details,
+      const content::FrameNavigateParams& params) override {
+    // If the embedder navigates to a different page then destroy the guest.
+    if (details.is_navigation_to_different_page())
+      Destroy();
+  }
+
+  void RenderProcessGone(base::TerminationStatus status) override {
+    // If the embedder crashes, then destroy the guest.
+    Destroy();
+  }
+
+  void DidToggleFullscreenModeForTab(bool entered_fullscreen) override {
+    if (destroyed_)
+      return;
+
+    is_fullscreen_ = entered_fullscreen;
+    guest_->EmbedderFullscreenToggled(is_fullscreen_);
+  }
+
+  void MainFrameWasResized(bool width_changed) override {
+    if (destroyed_)
+      return;
+
+    if (!web_contents()->GetDelegate())
+      return;
+
+    bool current_fullscreen =
+        web_contents()->GetDelegate()->IsFullscreenForTabOrPending(
+            web_contents());
+    if (is_fullscreen_ && !current_fullscreen) {
+      is_fullscreen_ = false;
+      guest_->EmbedderFullscreenToggled(is_fullscreen_);
+    }
+  }
+
+ private:
+  bool is_fullscreen_;
+  bool destroyed_;
+  GuestViewBase* guest_;
+
+  void Destroy() {
+    if (destroyed_)
+      return;
+
+    destroyed_ = true;
+    guest_->EmbedderWillBeDestroyed();
+    guest_->Destroy();
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(OwnerContentsObserver);
+};
+
+// This observer ensures that the GuestViewBase destroys itself when its
+// embedder goes away.
+class GuestViewBase::OpenerLifetimeObserver : public WebContentsObserver {
+ public:
+  OpenerLifetimeObserver(GuestViewBase* guest)
+      : WebContentsObserver(guest->GetOpener()->web_contents()),
+        guest_(guest) {}
+
+  ~OpenerLifetimeObserver() override {}
+
+  // WebContentsObserver implementation.
+  void WebContentsDestroyed() override {
+    if (guest_->attached())
+      return;
+
+    // If the opener is destroyed then destroy the guest.
+    guest_->Destroy();
+  }
+
+ private:
+  GuestViewBase* guest_;
+
+  DISALLOW_COPY_AND_ASSIGN(OpenerLifetimeObserver);
+};
+
+GuestViewBase::GuestViewBase(content::WebContents* owner_web_contents)
+    : owner_web_contents_(owner_web_contents),
+      browser_context_(owner_web_contents->GetBrowserContext()),
+      guest_instance_id_(
+          GuestViewManager::FromBrowserContext(browser_context_)->
+              GetNextInstanceID()),
+      view_instance_id_(kInstanceIDNone),
+      element_instance_id_(kInstanceIDNone),
+      initialized_(false),
+      is_being_destroyed_(false),
+      guest_host_(nullptr),
+      auto_size_enabled_(false),
+      is_full_page_plugin_(false),
+      guest_proxy_routing_id_(MSG_ROUTING_NONE),
+      weak_ptr_factory_(this) {
+  owner_host_ = GuestViewManager::FromBrowserContext(browser_context_)->
+      IsOwnedByExtension(this) ?
+          owner_web_contents->GetLastCommittedURL().host() : std::string();
+}
+
+void GuestViewBase::Init(const base::DictionaryValue& create_params,
+                         const WebContentsCreatedCallback& callback) {
+  if (initialized_)
+    return;
+  initialized_ = true;
+
+  if (!GuestViewManager::FromBrowserContext(browser_context_)->
+          IsGuestAvailableToContext(this)) {
+    // The derived class did not create a WebContents so this class serves no
+    // purpose. Let's self-destruct.
+    delete this;
+    callback.Run(nullptr);
+    return;
+  }
+
+  scoped_ptr<base::DictionaryValue> params(create_params.DeepCopy());
+  CreateWebContents(create_params,
+                    base::Bind(&GuestViewBase::CompleteInit,
+                               weak_ptr_factory_.GetWeakPtr(),
+                               base::Passed(&params),
+                               callback));
+}
+
+void GuestViewBase::InitWithWebContents(
+    const base::DictionaryValue& create_params,
+    content::WebContents* guest_web_contents) {
+  DCHECK(guest_web_contents);
+
+  // Create a ZoomController to allow the guest's contents to be zoomed.
+  // Do this before adding the GuestView as a WebContents Observer so that
+  // the GuestView and its derived classes can re-configure the ZoomController
+  // after the latter has handled WebContentsObserver events (observers are
+  // notified of events in the same order they are added as observers). For
+  // example, GuestViewBase may wish to put its guest into isolated zoom mode
+  // in DidNavigateMainFrame, but since ZoomController always resets to default
+  // zoom mode on this event, GuestViewBase would need to do so after
+  // ZoomController::DidNavigateMainFrame has completed.
+  ui_zoom::ZoomController::CreateForWebContents(guest_web_contents);
+
+  // At this point, we have just created the guest WebContents, we need to add
+  // an observer to the owner WebContents. This observer will be responsible
+  // for destroying the guest WebContents if the owner goes away.
+  owner_contents_observer_.reset(
+      new OwnerContentsObserver(this, owner_web_contents_));
+
+  WebContentsObserver::Observe(guest_web_contents);
+  guest_web_contents->SetDelegate(this);
+  webcontents_guestview_map.Get().insert(
+      std::make_pair(guest_web_contents, this));
+  GuestViewManager::FromBrowserContext(browser_context_)->
+      AddGuest(guest_instance_id_, guest_web_contents);
+
+  // Populate the view instance ID if we have it on creation.
+  create_params.GetInteger(kParameterInstanceId, &view_instance_id_);
+
+  if (CanRunInDetachedState())
+    SetUpSizing(create_params);
+
+  // Observe guest zoom changes.
+  auto zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(web_contents());
+  zoom_controller->AddObserver(this);
+
+  // Give the derived class an opportunity to perform additional initialization.
+  DidInitialize(create_params);
+}
+
+void GuestViewBase::LoadURLWithParams(
+      const content::NavigationController::LoadURLParams& load_params) {
+  int guest_proxy_routing_id = host()->LoadURLWithParams(load_params);
+  DCHECK(guest_proxy_routing_id_ == MSG_ROUTING_NONE ||
+         guest_proxy_routing_id == guest_proxy_routing_id_);
+  guest_proxy_routing_id_ = guest_proxy_routing_id;
+}
+
+void GuestViewBase::DispatchOnResizeEvent(const gfx::Size& old_size,
+                                          const gfx::Size& new_size) {
+  if (new_size == old_size)
+    return;
+
+  // Dispatch the onResize event.
+  scoped_ptr<base::DictionaryValue> args(new base::DictionaryValue());
+  args->SetInteger(kOldWidth, old_size.width());
+  args->SetInteger(kOldHeight, old_size.height());
+  args->SetInteger(kNewWidth, new_size.width());
+  args->SetInteger(kNewHeight, new_size.height());
+  DispatchEventToGuestProxy(new GuestViewEvent(kEventResize, args.Pass()));
+}
+
+gfx::Size GuestViewBase::GetDefaultSize() const {
+  if (is_full_page_plugin()) {
+    // Full page plugins default to the size of the owner's viewport.
+    return owner_web_contents()
+        ->GetRenderWidgetHostView()
+        ->GetVisibleViewportSize();
+  } else {
+    return gfx::Size(kDefaultWidth, kDefaultHeight);
+  }
+}
+
+void GuestViewBase::SetSize(const SetSizeParams& params) {
+  bool enable_auto_size =
+      params.enable_auto_size ? *params.enable_auto_size : auto_size_enabled_;
+  gfx::Size min_size = params.min_size ? *params.min_size : min_auto_size_;
+  gfx::Size max_size = params.max_size ? *params.max_size : max_auto_size_;
+
+  if (params.normal_size)
+    normal_size_ = *params.normal_size;
+
+  min_auto_size_ = min_size;
+  min_auto_size_.SetToMin(max_size);
+  max_auto_size_ = max_size;
+  max_auto_size_.SetToMax(min_size);
+
+  enable_auto_size &= !min_auto_size_.IsEmpty() && !max_auto_size_.IsEmpty() &&
+                      IsAutoSizeSupported();
+
+  content::RenderViewHost* rvh = web_contents()->GetRenderViewHost();
+  if (enable_auto_size) {
+    // Autosize is being enabled.
+    rvh->EnableAutoResize(min_auto_size_, max_auto_size_);
+    normal_size_.SetSize(0, 0);
+  } else {
+    // Autosize is being disabled.
+    // Use default width/height if missing from partially defined normal size.
+    if (normal_size_.width() && !normal_size_.height())
+      normal_size_.set_height(GetDefaultSize().height());
+    if (!normal_size_.width() && normal_size_.height())
+      normal_size_.set_width(GetDefaultSize().width());
+
+    gfx::Size new_size;
+    if (!normal_size_.IsEmpty()) {
+      new_size = normal_size_;
+    } else if (!guest_size_.IsEmpty()) {
+      new_size = guest_size_;
+    } else {
+      new_size = GetDefaultSize();
+    }
+
+    if (auto_size_enabled_) {
+      // Autosize was previously enabled.
+      rvh->DisableAutoResize(new_size);
+      GuestSizeChangedDueToAutoSize(guest_size_, new_size);
+    } else {
+      // Autosize was already disabled.
+      guest_host_->SizeContents(new_size);
+    }
+
+    DispatchOnResizeEvent(guest_size_, new_size);
+    guest_size_ = new_size;
+  }
+
+  auto_size_enabled_ = enable_auto_size;
+}
+
+// static
+GuestViewBase* GuestViewBase::FromWebContents(const WebContents* web_contents) {
+  WebContentsGuestViewMap* guest_map = webcontents_guestview_map.Pointer();
+  auto it = guest_map->find(web_contents);
+  return it == guest_map->end() ? nullptr : it->second;
+}
+
+// static
+GuestViewBase* GuestViewBase::From(int owner_process_id,
+                                   int guest_instance_id) {
+  auto host = content::RenderProcessHost::FromID(owner_process_id);
+  if (!host)
+    return nullptr;
+
+  content::WebContents* guest_web_contents =
+      GuestViewManager::FromBrowserContext(
+          host->GetBrowserContext())->
+              GetGuestByInstanceIDSafely(guest_instance_id, owner_process_id);
+  if (!guest_web_contents)
+    return nullptr;
+
+  return GuestViewBase::FromWebContents(guest_web_contents);
+}
+
+// static
+WebContents* GuestViewBase::GetTopLevelWebContents(WebContents* web_contents) {
+  while (GuestViewBase* guest = FromWebContents(web_contents))
+    web_contents = guest->owner_web_contents();
+  return web_contents;
+}
+
+// static
+bool GuestViewBase::IsGuest(WebContents* web_contents) {
+  return !!GuestViewBase::FromWebContents(web_contents);
+}
+
+bool GuestViewBase::IsAutoSizeSupported() const {
+  return false;
+}
+
+bool GuestViewBase::IsPreferredSizeModeEnabled() const {
+  return false;
+}
+
+bool GuestViewBase::IsDragAndDropEnabled() const {
+  return false;
+}
+
+bool GuestViewBase::ZoomPropagatesFromEmbedderToGuest() const {
+  return true;
+}
+
+content::WebContents* GuestViewBase::CreateNewGuestWindow(
+    const content::WebContents::CreateParams& create_params) {
+  auto guest_manager = GuestViewManager::FromBrowserContext(browser_context());
+  return guest_manager->CreateGuestWithWebContentsParams(
+      GetViewType(),
+      owner_web_contents(),
+      create_params);
+}
+
+void GuestViewBase::DidAttach(int guest_proxy_routing_id) {
+  DCHECK(guest_proxy_routing_id_ == MSG_ROUTING_NONE ||
+         guest_proxy_routing_id == guest_proxy_routing_id_);
+  guest_proxy_routing_id_ = guest_proxy_routing_id;
+
+  opener_lifetime_observer_.reset();
+
+  SetUpSizing(*attach_params());
+
+  // Give the derived class an opportunity to perform some actions.
+  DidAttachToEmbedder();
+
+  // Inform the associated GuestViewContainer that the contentWindow is ready.
+  embedder_web_contents()->Send(new GuestViewMsg_GuestAttached(
+      element_instance_id_,
+      guest_proxy_routing_id));
+
+  SendQueuedEvents();
+}
+
+void GuestViewBase::DidDetach() {
+  GuestViewManager::FromBrowserContext(browser_context_)->DetachGuest(this);
+  StopTrackingEmbedderZoomLevel();
+  owner_web_contents()->Send(new GuestViewMsg_GuestDetached(
+      element_instance_id_));
+  element_instance_id_ = kInstanceIDNone;
+}
+
+WebContents* GuestViewBase::GetOwnerWebContents() const {
+  return owner_web_contents_;
+}
+
+void GuestViewBase::GuestSizeChanged(const gfx::Size& new_size) {
+  if (!auto_size_enabled_)
+    return;
+  GuestSizeChangedDueToAutoSize(guest_size_, new_size);
+  DispatchOnResizeEvent(guest_size_, new_size);
+  guest_size_ = new_size;
+}
+
+const GURL& GuestViewBase::GetOwnerSiteURL() const {
+  return owner_web_contents()->GetLastCommittedURL();
+}
+
+void GuestViewBase::Destroy() {
+  if (is_being_destroyed_)
+    return;
+
+  is_being_destroyed_ = true;
+
+  // It is important to clear owner_web_contents_ after the call to
+  // StopTrackingEmbedderZoomLevel(), but before the rest of
+  // the statements in this function.
+  StopTrackingEmbedderZoomLevel();
+  owner_web_contents_ = nullptr;
+
+  DCHECK(web_contents());
+
+  // Give the derived class an opportunity to perform some cleanup.
+  WillDestroy();
+
+  // Invalidate weak pointers now so that bound callbacks cannot be called late
+  // into destruction. We must call this after WillDestroy because derived types
+  // may wish to access their openers.
+  weak_ptr_factory_.InvalidateWeakPtrs();
+
+  // Give the content module an opportunity to perform some cleanup.
+  guest_host_->WillDestroy();
+  guest_host_ = nullptr;
+
+  webcontents_guestview_map.Get().erase(web_contents());
+  GuestViewManager::FromBrowserContext(browser_context_)->
+      RemoveGuest(guest_instance_id_);
+  pending_events_.clear();
+
+  delete web_contents();
+}
+
+void GuestViewBase::SetAttachParams(const base::DictionaryValue& params) {
+  attach_params_.reset(params.DeepCopy());
+  attach_params_->GetInteger(kParameterInstanceId, &view_instance_id_);
+}
+
+void GuestViewBase::SetOpener(GuestViewBase* guest) {
+  if (guest && guest->IsViewType(GetViewType())) {
+    opener_ = guest->weak_ptr_factory_.GetWeakPtr();
+    if (!attached())
+      opener_lifetime_observer_.reset(new OpenerLifetimeObserver(this));
+    return;
+  }
+  opener_ = base::WeakPtr<GuestViewBase>();
+  opener_lifetime_observer_.reset();
+}
+
+void GuestViewBase::SetGuestHost(content::GuestHost* guest_host) {
+  guest_host_ = guest_host;
+}
+
+void GuestViewBase::WillAttach(content::WebContents* embedder_web_contents,
+                               int element_instance_id,
+                               bool is_full_page_plugin) {
+  if (owner_web_contents_ != embedder_web_contents) {
+    DCHECK_EQ(owner_contents_observer_->web_contents(), owner_web_contents_);
+    // Stop tracking the old embedder's zoom level.
+    StopTrackingEmbedderZoomLevel();
+    owner_web_contents_ = embedder_web_contents;
+    owner_contents_observer_.reset(
+        new OwnerContentsObserver(this, embedder_web_contents));
+    owner_host_ = GuestViewManager::FromBrowserContext(browser_context_)->
+        IsOwnedByExtension(this) ?
+            owner_web_contents()->GetLastCommittedURL().host() : std::string();
+  }
+
+  // Start tracking the new embedder's zoom level.
+  StartTrackingEmbedderZoomLevel();
+  element_instance_id_ = element_instance_id;
+  is_full_page_plugin_ = is_full_page_plugin;
+
+  WillAttachToEmbedder();
+}
+
+int GuestViewBase::LogicalPixelsToPhysicalPixels(double logical_pixels) const {
+  DCHECK(logical_pixels >= 0);
+  double zoom_factor = GetEmbedderZoomFactor();
+  return lround(logical_pixels * zoom_factor);
+}
+
+double GuestViewBase::PhysicalPixelsToLogicalPixels(int physical_pixels) const {
+  DCHECK(physical_pixels >= 0);
+  double zoom_factor = GetEmbedderZoomFactor();
+  return physical_pixels / zoom_factor;
+}
+
+void GuestViewBase::DidStopLoading() {
+  content::RenderViewHost* rvh = web_contents()->GetRenderViewHost();
+
+  if (IsPreferredSizeModeEnabled())
+    rvh->EnablePreferredSizeMode();
+  if (!IsDragAndDropEnabled()) {
+    const char script[] =
+        "window.addEventListener('dragstart', function() { "
+        "  window.event.preventDefault(); "
+        "});";
+    rvh->GetMainFrame()->ExecuteJavaScript(base::ASCIIToUTF16(script));
+  }
+  GuestViewDidStopLoading();
+}
+
+void GuestViewBase::RenderViewReady() {
+  GuestReady();
+}
+
+void GuestViewBase::WebContentsDestroyed() {
+  // Let the derived class know that its WebContents is in the process of
+  // being destroyed. web_contents() is still valid at this point.
+  // TODO(fsamuel): This allows for reentrant code into WebContents during
+  // destruction. This could potentially lead to bugs. Perhaps we should get rid
+  // of this?
+  GuestDestroyed();
+
+  // Self-destruct.
+  delete this;
+}
+
+void GuestViewBase::DidNavigateMainFrame(
+    const content::LoadCommittedDetails& details,
+    const content::FrameNavigateParams& params) {
+  if (attached() && ZoomPropagatesFromEmbedderToGuest())
+    SetGuestZoomLevelToMatchEmbedder();
+}
+
+void GuestViewBase::ActivateContents(WebContents* web_contents) {
+  if (!attached() || !embedder_web_contents()->GetDelegate())
+    return;
+
+  embedder_web_contents()->GetDelegate()->ActivateContents(
+      embedder_web_contents());
+}
+
+void GuestViewBase::DeactivateContents(WebContents* web_contents) {
+  if (!attached() || !embedder_web_contents()->GetDelegate())
+    return;
+
+  embedder_web_contents()->GetDelegate()->DeactivateContents(
+      embedder_web_contents());
+}
+
+void GuestViewBase::ContentsMouseEvent(content::WebContents* source,
+                                       const gfx::Point& location,
+                                       bool motion) {
+  if (!attached() || !embedder_web_contents()->GetDelegate())
+    return;
+
+  embedder_web_contents()->GetDelegate()->ContentsMouseEvent(
+      embedder_web_contents(), location, motion);
+}
+
+void GuestViewBase::ContentsZoomChange(bool zoom_in) {
+  ui_zoom::PageZoom::Zoom(
+      embedder_web_contents(),
+      zoom_in ? content::PAGE_ZOOM_IN : content::PAGE_ZOOM_OUT);
+}
+
+void GuestViewBase::HandleKeyboardEvent(
+    WebContents* source,
+    const content::NativeWebKeyboardEvent& event) {
+  if (!attached())
+    return;
+
+  // Send the keyboard events back to the embedder to reprocess them.
+  embedder_web_contents()->GetDelegate()->
+      HandleKeyboardEvent(embedder_web_contents(), event);
+}
+
+void GuestViewBase::LoadingStateChanged(content::WebContents* source,
+                                        bool to_different_document) {
+  if (!attached() || !embedder_web_contents()->GetDelegate())
+    return;
+
+  embedder_web_contents()->GetDelegate()->LoadingStateChanged(
+      embedder_web_contents(), to_different_document);
+}
+
+content::ColorChooser* GuestViewBase::OpenColorChooser(
+    WebContents* web_contents,
+    SkColor color,
+    const std::vector<content::ColorSuggestion>& suggestions) {
+  if (!attached() || !embedder_web_contents()->GetDelegate())
+    return nullptr;
+
+  return embedder_web_contents()->GetDelegate()->OpenColorChooser(
+      web_contents, color, suggestions);
+}
+
+void GuestViewBase::RunFileChooser(WebContents* web_contents,
+                                   const content::FileChooserParams& params) {
+  if (!attached() || !embedder_web_contents()->GetDelegate())
+    return;
+
+  embedder_web_contents()->GetDelegate()->RunFileChooser(web_contents, params);
+}
+
+bool GuestViewBase::ShouldFocusPageAfterCrash() {
+  // Focus is managed elsewhere.
+  return false;
+}
+
+bool GuestViewBase::PreHandleGestureEvent(content::WebContents* source,
+                                         const blink::WebGestureEvent& event) {
+  return event.type == blink::WebGestureEvent::GesturePinchBegin ||
+      event.type == blink::WebGestureEvent::GesturePinchUpdate ||
+      event.type == blink::WebGestureEvent::GesturePinchEnd;
+}
+
+void GuestViewBase::UpdatePreferredSize(
+    content::WebContents* target_web_contents,
+    const gfx::Size& pref_size) {
+  // In theory it's not necessary to check IsPreferredSizeModeEnabled() because
+  // there will only be events if it was enabled in the first place. However,
+  // something else may have turned on preferred size mode, so double check.
+  DCHECK_EQ(web_contents(), target_web_contents);
+  if (IsPreferredSizeModeEnabled()) {
+    OnPreferredSizeChanged(pref_size);
+  }
+}
+
+void GuestViewBase::UpdateTargetURL(content::WebContents* source,
+                                    const GURL& url) {
+  if (!attached() || !embedder_web_contents()->GetDelegate())
+    return;
+
+  embedder_web_contents()->GetDelegate()->UpdateTargetURL(
+      embedder_web_contents(), url);
+}
+
+bool GuestViewBase::ShouldResumeRequestsForCreatedWindow() {
+  return false;
+}
+
+GuestViewBase::~GuestViewBase() {
+}
+
+void GuestViewBase::OnZoomChanged(
+    const ui_zoom::ZoomController::ZoomChangedEventData& data) {
+  if (data.web_contents == embedder_web_contents()) {
+    // The embedder's zoom level has changed.
+    auto guest_zoom_controller =
+        ui_zoom::ZoomController::FromWebContents(web_contents());
+    if (content::ZoomValuesEqual(data.new_zoom_level,
+                                 guest_zoom_controller->GetZoomLevel())) {
+      return;
+    }
+    // When the embedder's zoom level doesn't match the guest's, then update the
+    // guest's zoom level to match.
+    guest_zoom_controller->SetZoomLevel(data.new_zoom_level);
+
+    EmbedderZoomChanged(data.old_zoom_level, data.new_zoom_level);
+    return;
+  }
+
+  if (data.web_contents == web_contents()) {
+    // The guest's zoom level has changed.
+    GuestZoomChanged(data.old_zoom_level, data.new_zoom_level);
+  }
+}
+
+void GuestViewBase::DispatchEventToGuestProxy(GuestViewEvent* event) {
+  event->Dispatch(this, guest_instance_id_);
+}
+
+void GuestViewBase::DispatchEventToView(GuestViewEvent* event) {
+  if (!attached() &&
+      (!CanRunInDetachedState() || !can_owner_receive_events())) {
+    pending_events_.push_back(linked_ptr<GuestViewEvent>(event));
+    return;
+  }
+
+  event->Dispatch(this, view_instance_id_);
+}
+
+void GuestViewBase::SendQueuedEvents() {
+  if (!attached())
+    return;
+  while (!pending_events_.empty()) {
+    linked_ptr<GuestViewEvent> event_ptr = pending_events_.front();
+    pending_events_.pop_front();
+    event_ptr.release()->Dispatch(this, view_instance_id_);
+  }
+}
+
+void GuestViewBase::CompleteInit(
+    scoped_ptr<base::DictionaryValue> create_params,
+    const WebContentsCreatedCallback& callback,
+    content::WebContents* guest_web_contents) {
+  if (!guest_web_contents) {
+    // The derived class did not create a WebContents so this class serves no
+    // purpose. Let's self-destruct.
+    delete this;
+    callback.Run(nullptr);
+    return;
+  }
+  InitWithWebContents(*create_params, guest_web_contents);
+  callback.Run(guest_web_contents);
+}
+
+double GuestViewBase::GetEmbedderZoomFactor() const {
+  if (!embedder_web_contents())
+    return 1.0;
+
+  return content::ZoomLevelToZoomFactor(
+      ui_zoom::ZoomController::GetZoomLevelForWebContents(
+          embedder_web_contents()));
+}
+
+void GuestViewBase::SetUpSizing(const base::DictionaryValue& params) {
+  // Read the autosize parameters passed in from the embedder.
+  bool auto_size_enabled = auto_size_enabled_;
+  params.GetBoolean(kAttributeAutoSize, &auto_size_enabled);
+
+  int max_height = max_auto_size_.height();
+  int max_width = max_auto_size_.width();
+  params.GetInteger(kAttributeMaxHeight, &max_height);
+  params.GetInteger(kAttributeMaxWidth, &max_width);
+
+  int min_height = min_auto_size_.height();
+  int min_width = min_auto_size_.width();
+  params.GetInteger(kAttributeMinHeight, &min_height);
+  params.GetInteger(kAttributeMinWidth, &min_width);
+
+  double element_height = 0.0;
+  double element_width = 0.0;
+  params.GetDouble(kElementHeight, &element_height);
+  params.GetDouble(kElementWidth, &element_width);
+
+  // Set the normal size to the element size so that the guestview will fit
+  // the element initially if autosize is disabled.
+  int normal_height = normal_size_.height();
+  int normal_width = normal_size_.width();
+  // If the element size was provided in logical units (versus physical), then
+  // it will be converted to physical units.
+  bool element_size_is_logical = false;
+  params.GetBoolean(kElementSizeIsLogical, &element_size_is_logical);
+  if (element_size_is_logical) {
+    // Convert the element size from logical pixels to physical pixels.
+    normal_height = LogicalPixelsToPhysicalPixels(element_height);
+    normal_width = LogicalPixelsToPhysicalPixels(element_width);
+  } else {
+    normal_height = lround(element_height);
+    normal_width = lround(element_width);
+  }
+
+  SetSizeParams set_size_params;
+  set_size_params.enable_auto_size.reset(new bool(auto_size_enabled));
+  set_size_params.min_size.reset(new gfx::Size(min_width, min_height));
+  set_size_params.max_size.reset(new gfx::Size(max_width, max_height));
+  set_size_params.normal_size.reset(new gfx::Size(normal_width, normal_height));
+
+  // Call SetSize to apply all the appropriate validation and clipping of
+  // values.
+  SetSize(set_size_params);
+}
+
+void GuestViewBase::SetGuestZoomLevelToMatchEmbedder() {
+  auto embedder_zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(owner_web_contents());
+  if (!embedder_zoom_controller)
+    return;
+
+  ui_zoom::ZoomController::FromWebContents(web_contents())
+      ->SetZoomLevel(embedder_zoom_controller->GetZoomLevel());
+}
+
+void GuestViewBase::StartTrackingEmbedderZoomLevel() {
+  if (!ZoomPropagatesFromEmbedderToGuest())
+    return;
+
+  auto embedder_zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(owner_web_contents());
+  // Chrome Apps do not have a ZoomController.
+  if (!embedder_zoom_controller)
+    return;
+  // Listen to the embedder's zoom changes.
+  embedder_zoom_controller->AddObserver(this);
+
+  // Set the guest's initial zoom level to be equal to the embedder's.
+  SetGuestZoomLevelToMatchEmbedder();
+}
+
+void GuestViewBase::StopTrackingEmbedderZoomLevel() {
+  if (!attached() || !ZoomPropagatesFromEmbedderToGuest())
+    return;
+
+  auto embedder_zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(owner_web_contents());
+  // Chrome Apps do not have a ZoomController.
+  if (!embedder_zoom_controller)
+    return;
+  embedder_zoom_controller->RemoveObserver(this);
+}
+
+}  // namespace guest_view
diff --git a/components/guest_view/browser/guest_view_base.h b/components/guest_view/browser/guest_view_base.h
new file mode 100644
index 0000000..74fb59c
--- /dev/null
+++ b/components/guest_view/browser/guest_view_base.h
@@ -0,0 +1,458 @@
+// 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 COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_BASE_H_
+#define COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_BASE_H_
+
+#include <queue>
+
+#include "base/memory/weak_ptr.h"
+#include "base/values.h"
+#include "components/guest_view/common/guest_view_constants.h"
+#include "components/ui/zoom/zoom_observer.h"
+#include "content/public/browser/browser_plugin_guest_delegate.h"
+#include "content/public/browser/guest_host.h"
+#include "content/public/browser/render_process_host_observer.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_delegate.h"
+#include "content/public/browser/web_contents_observer.h"
+
+struct RendererContentSettingRules;
+
+namespace guest_view {
+
+class GuestViewEvent;
+
+// A struct of parameters for SetSize(). The parameters are all declared as
+// scoped pointers since they are all optional. Null pointers indicate that the
+// parameter has not been provided, and the last used value should be used. Note
+// that when |enable_auto_size| is true, providing |normal_size| is not
+// meaningful. This is because the normal size of the guestview is overridden
+// whenever autosizing occurs.
+struct SetSizeParams {
+  SetSizeParams();
+  ~SetSizeParams();
+
+  scoped_ptr<bool> enable_auto_size;
+  scoped_ptr<gfx::Size> min_size;
+  scoped_ptr<gfx::Size> max_size;
+  scoped_ptr<gfx::Size> normal_size;
+};
+
+// A GuestViewBase is the base class browser-side API implementation for a
+// <*view> tag. GuestViewBase maintains an association between a guest
+// WebContents and an owner WebContents. It receives events issued from
+// the guest and relays them to the owner. GuestViewBase tracks the lifetime
+// of its owner. A GuestViewBase's owner is referred to as an embedder if
+// it is attached to a container within the owner's WebContents.
+class GuestViewBase : public content::BrowserPluginGuestDelegate,
+                      public content::WebContentsDelegate,
+                      public content::WebContentsObserver,
+                      public ui_zoom::ZoomObserver {
+ public:
+  // Returns a *ViewGuest if this GuestView is of the given view type.
+  template <typename T>
+  T* As() {
+    if (IsViewType(T::Type))
+      return static_cast<T*>(this);
+
+    return nullptr;
+  }
+
+  static GuestViewBase* FromWebContents(
+      const content::WebContents* web_contents);
+
+  static GuestViewBase* From(int owner_process_id, int instance_id);
+
+  // Given a |web_contents|, returns the top level owner WebContents. If
+  // |web_contents| does not belong to a GuestView, it will be returned
+  // unchanged.
+  static content::WebContents* GetTopLevelWebContents(
+      content::WebContents* web_contents);
+
+  static bool IsGuest(content::WebContents* web_contents);
+
+  virtual const char* GetViewType() const = 0;
+
+  // This method is called after the guest has been attached to an embedder and
+  // suspended resource loads have been resumed.
+  //
+  // This method can be overriden by subclasses. This gives the derived class
+  // an opportunity to perform setup actions after attachment.
+  virtual void DidAttachToEmbedder() {}
+
+  // This method is called after this GuestViewBase has been initiated.
+  //
+  // This gives the derived class an opportunity to perform additional
+  // initialization.
+  virtual void DidInitialize(const base::DictionaryValue& create_params) {}
+
+  // This method is called when the initial set of frames within the page have
+  // completed loading.
+  virtual void GuestViewDidStopLoading() {}
+
+  // This method is called before the embedder is destroyed.
+  // |owner_web_contents_| should still be valid during this call. This
+  // allows the derived class to perform some cleanup related to the embedder
+  // web contents.
+  virtual void EmbedderWillBeDestroyed() {}
+
+  // This method is called when the embedder's zoom changes.
+  virtual void EmbedderZoomChanged(double old_zoom_level,
+                                   double new_zoom_level) {}
+
+  // This method is called when the guest WebContents has been destroyed. This
+  // object will be destroyed after this call returns.
+  //
+  // This gives the derived class an opportunity to perform some cleanup.
+  virtual void GuestDestroyed() {}
+
+  // This method is invoked when the guest RenderView is ready, e.g. because we
+  // recreated it after a crash or after reattachment.
+  //
+  // This gives the derived class an opportunity to perform some initialization
+  // work.
+  virtual void GuestReady() {}
+
+  // This method is called when the guest's zoom changes.
+  virtual void GuestZoomChanged(double old_zoom_level, double new_zoom_level) {}
+
+  // This method is called when embedder WebContents's fullscreen is toggled.
+  //
+  // If the guest asked the embedder to enter fullscreen, the guest uses this
+  // signal to exit fullscreen state.
+  virtual void EmbedderFullscreenToggled(bool entered_fullscreen) {}
+
+  // This method is invoked when the contents auto-resized to give the container
+  // an opportunity to match it if it wishes.
+  //
+  // This gives the derived class an opportunity to inform its container element
+  // or perform other actions.
+  virtual void GuestSizeChangedDueToAutoSize(const gfx::Size& old_size,
+                                             const gfx::Size& new_size) {}
+
+  // This method queries whether autosize is supported for this particular view.
+  // By default, autosize is not supported. Derived classes can override this
+  // behavior to support autosize.
+  virtual bool IsAutoSizeSupported() const;
+
+  // This method is invoked when the contents preferred size changes. This will
+  // only ever fire if IsPreferredSizeSupported returns true.
+  virtual void OnPreferredSizeChanged(const gfx::Size& pref_size) {}
+
+  // This method queries whether preferred size events are enabled for this
+  // view. By default, preferred size events are disabled, since they add a
+  // small amount of overhead.
+  virtual bool IsPreferredSizeModeEnabled() const;
+
+  // This method queries whether drag-and-drop is enabled for this particular
+  // view. By default, drag-and-drop is disabled. Derived classes can override
+  // this behavior to enable drag-and-drop.
+  virtual bool IsDragAndDropEnabled() const;
+
+  // This method is called immediately before suspended resource loads have been
+  // resumed on attachment to an embedder.
+  //
+  // This method can be overriden by subclasses. This gives the derived class
+  // an opportunity to perform setup actions before attachment.
+  virtual void WillAttachToEmbedder() {}
+
+  // This method is called when the guest WebContents is about to be destroyed.
+  //
+  // This gives the derived class an opportunity to perform some cleanup prior
+  // to destruction.
+  virtual void WillDestroy() {}
+
+  // This method is to be implemented by the derived class. This indicates
+  // whether zoom should propagate from the embedder to the guest content.
+  virtual bool ZoomPropagatesFromEmbedderToGuest() const;
+
+  // This method is to be implemented by the derived class. Access to guest
+  // views are determined by the availability of the internal extension API
+  // used to implement the guest view.
+  //
+  // This should be the name of the API as it appears in the _api_features.json
+  // file.
+  virtual const char* GetAPINamespace() const = 0;
+
+  // This method is to be implemented by the derived class. This method is the
+  // task prefix to show for a task produced by this GuestViewBase's derived
+  // type.
+  virtual int GetTaskPrefix() const = 0;
+
+  // This method is to be implemented by the derived class. Given a set of
+  // initialization parameters, a concrete subclass of GuestViewBase can
+  // create a specialized WebContents that it returns back to GuestViewBase.
+  using WebContentsCreatedCallback =
+      base::Callback<void(content::WebContents*)>;
+  virtual void CreateWebContents(
+      const base::DictionaryValue& create_params,
+      const WebContentsCreatedCallback& callback) = 0;
+
+  // This creates a WebContents and initializes |this| GuestViewBase to use the
+  // newly created WebContents.
+  void Init(const base::DictionaryValue& create_params,
+            const WebContentsCreatedCallback& callback);
+
+  void InitWithWebContents(const base::DictionaryValue& create_params,
+                           content::WebContents* guest_web_contents);
+
+  void LoadURLWithParams(
+      const content::NavigationController::LoadURLParams& load_params);
+
+  bool IsViewType(const char* const view_type) const {
+    return !strcmp(GetViewType(), view_type);
+  }
+
+  // Used to toggle autosize mode for this GuestView, and set both the automatic
+  // and normal sizes.
+  void SetSize(const SetSizeParams& params);
+
+  bool initialized() const { return initialized_; }
+
+  content::WebContents* embedder_web_contents() const {
+    return attached() ? owner_web_contents_ : nullptr;
+  }
+
+  content::WebContents* owner_web_contents() const {
+    return owner_web_contents_;
+  }
+
+  content::GuestHost* host() const {
+    return guest_host_;
+  }
+
+  // Returns the parameters associated with the element hosting this GuestView
+  // passed in from JavaScript.
+  base::DictionaryValue* attach_params() const { return attach_params_.get(); }
+
+  // Returns whether this guest has an associated embedder.
+  bool attached() const {
+    return element_instance_id_ != kInstanceIDNone;
+  }
+
+  // Returns the instance ID of the <*view> element.
+  int view_instance_id() const { return view_instance_id_; }
+
+  // Returns the instance ID of this GuestViewBase.
+  int guest_instance_id() const { return guest_instance_id_; }
+
+  // Returns the instance ID of the GuestViewBase's element.
+  int element_instance_id() const { return element_instance_id_; }
+
+  bool can_owner_receive_events() const { return !!view_instance_id_; }
+
+  // Returns the user browser context of the embedder.
+  content::BrowserContext* browser_context() const { return browser_context_; }
+
+  GuestViewBase* GetOpener() const {
+    return opener_.get();
+  }
+
+  // Returns the URL of the owner WebContents.
+  const GURL& GetOwnerSiteURL() const;
+
+  // Returns the host of the owner WebContents. For extensions, this is the
+  // extension ID.
+  std::string owner_host() const { return owner_host_; }
+
+  // Whether the guest view is inside a plugin document.
+  bool is_full_page_plugin() const { return is_full_page_plugin_; }
+
+  // Returns the routing ID of the guest proxy in the owner's renderer process.
+  // This value is only valid after attachment or first navigation.
+  int proxy_routing_id() const { return guest_proxy_routing_id_; }
+
+  // Destroy this guest.
+  void Destroy();
+
+  // Saves the attach state of the custom element hosting this GuestView.
+  void SetAttachParams(const base::DictionaryValue& params);
+  void SetOpener(GuestViewBase* opener);
+
+  // BrowserPluginGuestDelegate implementation.
+  content::WebContents* CreateNewGuestWindow(
+      const content::WebContents::CreateParams& create_params) final;
+  void DidAttach(int guest_proxy_routing_id) final;
+  void DidDetach() final;
+  content::WebContents* GetOwnerWebContents() const final;
+  void GuestSizeChanged(const gfx::Size& new_size) final;
+  void SetGuestHost(content::GuestHost* guest_host) final;
+  void WillAttach(content::WebContents* embedder_web_contents,
+                  int browser_plugin_instance_id,
+                  bool is_full_page_plugin) final;
+
+  // ui_zoom::ZoomObserver implementation.
+  void OnZoomChanged(
+      const ui_zoom::ZoomController::ZoomChangedEventData& data) final;
+
+  // Dispatches an event to the guest proxy.
+  void DispatchEventToGuestProxy(GuestViewEvent* event);
+
+  // Dispatches an event to the view.
+  void DispatchEventToView(GuestViewEvent* event);
+
+ protected:
+  explicit GuestViewBase(content::WebContents* owner_web_contents);
+
+  ~GuestViewBase() override;
+
+  // Convert sizes in pixels from logical to physical numbers of pixels.
+  // Note that a size can consist of a fractional number of logical pixels
+  // (hence |logical_pixels| is represented as a double), but will always
+  // consist of an integral number of physical pixels (hence the return value
+  // is represented as an int).
+  int LogicalPixelsToPhysicalPixels(double logical_pixels) const;
+
+  // Convert sizes in pixels from physical to logical numbers of pixels.
+  // Note that a size can consist of a fractional number of logical pixels
+  // (hence the return value is represented as a double), but will always
+  // consist of an integral number of physical pixels (hence |physical_pixels|
+  // is represented as an int).
+  double PhysicalPixelsToLogicalPixels(int physical_pixels) const;
+
+  // WebContentsObserver implementation.
+  void DidStopLoading() final;
+  void RenderViewReady() final;
+  void WebContentsDestroyed() final;
+  void DidNavigateMainFrame(
+      const content::LoadCommittedDetails& details,
+      const content::FrameNavigateParams& params) override;
+
+  // WebContentsDelegate implementation.
+  void ActivateContents(content::WebContents* contents) final;
+  void DeactivateContents(content::WebContents* contents) final;
+  void ContentsMouseEvent(content::WebContents* source,
+                          const gfx::Point& location,
+                          bool motion) override;
+  void ContentsZoomChange(bool zoom_in) override;
+  void HandleKeyboardEvent(
+      content::WebContents* source,
+      const content::NativeWebKeyboardEvent& event) override;
+  void LoadingStateChanged(content::WebContents* source,
+                           bool to_different_document) final;
+  content::ColorChooser* OpenColorChooser(
+      content::WebContents* web_contents,
+      SkColor color,
+      const std::vector<content::ColorSuggestion>& suggestions) override;
+  void RunFileChooser(content::WebContents* web_contents,
+                      const content::FileChooserParams& params) override;
+  bool ShouldFocusPageAfterCrash() final;
+  bool PreHandleGestureEvent(content::WebContents* source,
+                             const blink::WebGestureEvent& event) override;
+  void UpdatePreferredSize(content::WebContents* web_contents,
+                           const gfx::Size& pref_size) final;
+  void UpdateTargetURL(content::WebContents* source, const GURL& url) override;
+  bool ShouldResumeRequestsForCreatedWindow() override;
+
+  void SetGuestZoomLevelToMatchEmbedder();
+
+ private:
+  class OwnerContentsObserver;
+
+  class OpenerLifetimeObserver;
+
+  void SendQueuedEvents();
+
+  void CompleteInit(scoped_ptr<base::DictionaryValue> create_params,
+                    const WebContentsCreatedCallback& callback,
+                    content::WebContents* guest_web_contents);
+
+  // Dispatches the onResize event to the embedder.
+  void DispatchOnResizeEvent(const gfx::Size& old_size,
+                             const gfx::Size& new_size);
+
+  // Returns the default size of the guestview.
+  gfx::Size GetDefaultSize() const;
+
+  // Get the zoom factor for the embedder's web contents.
+  double GetEmbedderZoomFactor() const;
+
+  void SetUpSizing(const base::DictionaryValue& params);
+
+  void StartTrackingEmbedderZoomLevel();
+  void StopTrackingEmbedderZoomLevel();
+
+  // This guest tracks the lifetime of the WebContents specified by
+  // |owner_web_contents_|. If |owner_web_contents_| is destroyed then this
+  // guest will also self-destruct.
+  content::WebContents* owner_web_contents_;
+  std::string owner_host_;
+  content::BrowserContext* const browser_context_;
+
+  // |guest_instance_id_| is a profile-wide unique identifier for a guest
+  // WebContents.
+  const int guest_instance_id_;
+
+  // |view_instance_id_| is an identifier that's unique within a particular
+  // embedder RenderViewHost for a particular <*view> instance.
+  int view_instance_id_;
+
+  // |element_instance_id_| is an identifer that's unique to a particular
+  // GuestViewContainer element.
+  int element_instance_id_;
+
+  // |initialized_| indicates whether GuestViewBase::Init has been called for
+  // this object.
+  bool initialized_;
+
+  // Indicates that this guest is in the process of being destroyed.
+  bool is_being_destroyed_;
+
+  // This is a queue of Events that are destined to be sent to the embedder once
+  // the guest is attached to a particular embedder.
+  std::deque<linked_ptr<GuestViewEvent> > pending_events_;
+
+  // The opener guest view.
+  base::WeakPtr<GuestViewBase> opener_;
+
+  // The parameters associated with the element hosting this GuestView that
+  // are passed in from JavaScript. This will typically be the view instance ID,
+  // and element-specific parameters. These parameters are passed along to new
+  // guests that are created from this guest.
+  scoped_ptr<base::DictionaryValue> attach_params_;
+
+  // This observer ensures that this guest self-destructs if the embedder goes
+  // away.
+  scoped_ptr<OwnerContentsObserver> owner_contents_observer_;
+
+  // This observer ensures that if the guest is unattached and its opener goes
+  // away then this guest also self-destructs.
+  scoped_ptr<OpenerLifetimeObserver> opener_lifetime_observer_;
+
+  // The size of the guest content. Note: In autosize mode, the container
+  // element may not match the size of the guest.
+  gfx::Size guest_size_;
+
+  // A pointer to the guest_host.
+  content::GuestHost* guest_host_;
+
+  // Indicates whether autosize mode is enabled or not.
+  bool auto_size_enabled_;
+
+  // The maximum size constraints of the container element in autosize mode.
+  gfx::Size max_auto_size_;
+
+  // The minimum size constraints of the container element in autosize mode.
+  gfx::Size min_auto_size_;
+
+  // The size that will be used when autosize mode is disabled.
+  gfx::Size normal_size_;
+
+  // Whether the guest view is inside a plugin document.
+  bool is_full_page_plugin_;
+
+  // The routing ID of the proxy to the guest in the owner's renderer process.
+  int guest_proxy_routing_id_;
+
+  // This is used to ensure pending tasks will not fire after this object is
+  // destroyed.
+  base::WeakPtrFactory<GuestViewBase> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GuestViewBase);
+};
+
+}  // namespace guest_view
+
+#endif  // COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_BASE_H_
diff --git a/components/guest_view/browser/guest_view_event.cc b/components/guest_view/browser/guest_view_event.cc
new file mode 100644
index 0000000..a88d62f
--- /dev/null
+++ b/components/guest_view/browser/guest_view_event.cc
@@ -0,0 +1,28 @@
+// Copyright 2015 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 "components/guest_view/browser/guest_view_event.h"
+
+#include "components/guest_view/browser/guest_view_base.h"
+#include "components/guest_view/browser/guest_view_manager.h"
+
+namespace guest_view {
+
+GuestViewEvent::GuestViewEvent(const std::string& name,
+                               scoped_ptr<base::DictionaryValue> args)
+    : name_(name),
+      args_(args.Pass()) {
+}
+
+GuestViewEvent::~GuestViewEvent() {
+}
+
+void GuestViewEvent::Dispatch(GuestViewBase* guest, int instance_id) {
+  GuestViewManager::FromBrowserContext(guest->browser_context())->
+      DispatchEvent(name_, args_.Pass(), guest, instance_id);
+
+  delete this;
+}
+
+}  // namespace guest_view
diff --git a/components/guest_view/browser/guest_view_event.h b/components/guest_view/browser/guest_view_event.h
new file mode 100644
index 0000000..7f51d46
--- /dev/null
+++ b/components/guest_view/browser/guest_view_event.h
@@ -0,0 +1,41 @@
+// Copyright 2015 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 COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_EVENT_H_
+#define COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_EVENT_H_
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/values.h"
+
+namespace guest_view {
+
+class GuestViewBase;
+
+// A GuestViewEvent is a wrapper class for a GuestView event.
+// GuestViewEvents may be queued until the guest is attached to a container.
+// This wrapper class holds all the necessary information to fire the event
+// on attachment. GuestViewEvents are owned by GuestViewBase.
+class GuestViewEvent {
+ public:
+  GuestViewEvent(const std::string& name,
+                 scoped_ptr<base::DictionaryValue> args);
+  ~GuestViewEvent();
+
+  // This method will dispatch the event to the specified |guest|'s embedder and
+  // use the provided |instance_id| for routing. After dispatch, this object
+  // will self-destruct.
+  void Dispatch(GuestViewBase* guest, int instance_id);
+
+private:
+  const std::string name_;
+  scoped_ptr<base::DictionaryValue> args_;
+
+  DISALLOW_COPY_AND_ASSIGN(GuestViewEvent);
+};
+
+}  // namespace guest_view
+
+#endif  // COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_EVENT_H_
diff --git a/components/guest_view/browser/guest_view_manager.cc b/components/guest_view/browser/guest_view_manager.cc
new file mode 100644
index 0000000..04cc220
--- /dev/null
+++ b/components/guest_view/browser/guest_view_manager.cc
@@ -0,0 +1,376 @@
+// 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 "components/guest_view/browser/guest_view_manager.h"
+
+#include "base/macros.h"
+#include "base/strings/stringprintf.h"
+#include "components/guest_view/browser/guest_view_base.h"
+#include "components/guest_view/browser/guest_view_manager_delegate.h"
+#include "components/guest_view/browser/guest_view_manager_factory.h"
+#include "components/guest_view/common/guest_view_constants.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/user_metrics.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/common/child_process_host.h"
+#include "content/public/common/result_codes.h"
+#include "content/public/common/url_constants.h"
+#include "url/gurl.h"
+
+using content::BrowserContext;
+using content::SiteInstance;
+using content::WebContents;
+
+namespace guest_view {
+
+// static
+GuestViewManagerFactory* GuestViewManager::factory_ = nullptr;
+
+GuestViewManager::GuestViewManager(
+    content::BrowserContext* context,
+    scoped_ptr<GuestViewManagerDelegate> delegate)
+    : current_instance_id_(0),
+      last_instance_id_removed_(0),
+      context_(context),
+      delegate_(delegate.Pass()) {
+}
+
+GuestViewManager::~GuestViewManager() {}
+
+// static
+GuestViewManager* GuestViewManager::CreateWithDelegate(
+    BrowserContext* context,
+    scoped_ptr<GuestViewManagerDelegate> delegate) {
+  GuestViewManager* guest_manager = FromBrowserContext(context);
+  if (!guest_manager) {
+    if (factory_) {
+      guest_manager =
+          factory_->CreateGuestViewManager(context, delegate.Pass());
+    } else {
+      guest_manager = new GuestViewManager(context, delegate.Pass());
+    }
+    context->SetUserData(kGuestViewManagerKeyName, guest_manager);
+  }
+  return guest_manager;
+}
+
+// static
+GuestViewManager* GuestViewManager::FromBrowserContext(
+    BrowserContext* context) {
+  return static_cast<GuestViewManager*>(context->GetUserData(
+      kGuestViewManagerKeyName));
+}
+
+content::WebContents* GuestViewManager::GetGuestByInstanceIDSafely(
+    int guest_instance_id,
+    int embedder_render_process_id) {
+  if (!CanEmbedderAccessInstanceIDMaybeKill(embedder_render_process_id,
+                                            guest_instance_id)) {
+    return nullptr;
+  }
+  return GetGuestByInstanceID(guest_instance_id);
+}
+
+void GuestViewManager::AttachGuest(int embedder_process_id,
+                                   int element_instance_id,
+                                   int guest_instance_id,
+                                   const base::DictionaryValue& attach_params) {
+  auto guest_view = GuestViewBase::From(embedder_process_id, guest_instance_id);
+  if (!guest_view)
+    return;
+
+  ElementInstanceKey key(embedder_process_id, element_instance_id);
+  auto it = instance_id_map_.find(key);
+  // If there is an existing guest attached to the element, then destroy the
+  // existing guest.
+  if (it != instance_id_map_.end()) {
+    int old_guest_instance_id = it->second;
+    if (old_guest_instance_id == guest_instance_id)
+      return;
+
+    auto old_guest_view = GuestViewBase::From(embedder_process_id,
+                                              old_guest_instance_id);
+    old_guest_view->Destroy();
+  }
+  instance_id_map_[key] = guest_instance_id;
+  reverse_instance_id_map_[guest_instance_id] = key;
+  guest_view->SetAttachParams(attach_params);
+}
+
+void GuestViewManager::DetachGuest(GuestViewBase* guest) {
+  if (!guest->attached())
+    return;
+
+  auto reverse_it = reverse_instance_id_map_.find(guest->guest_instance_id());
+  if (reverse_it == reverse_instance_id_map_.end())
+    return;
+
+  const ElementInstanceKey& key = reverse_it->second;
+
+  auto it = instance_id_map_.find(key);
+  DCHECK(it != instance_id_map_.end());
+
+  reverse_instance_id_map_.erase(reverse_it);
+  instance_id_map_.erase(it);
+}
+
+bool GuestViewManager::IsOwnedByExtension(GuestViewBase* guest) {
+  return delegate_->IsOwnedByExtension(guest);
+}
+
+int GuestViewManager::GetNextInstanceID() {
+  return ++current_instance_id_;
+}
+
+void GuestViewManager::CreateGuest(const std::string& view_type,
+                                   content::WebContents* owner_web_contents,
+                                   const base::DictionaryValue& create_params,
+                                   const WebContentsCreatedCallback& callback) {
+  GuestViewBase* guest = CreateGuestInternal(owner_web_contents, view_type);
+  if (!guest) {
+    callback.Run(nullptr);
+    return;
+  }
+  guest->Init(create_params, callback);
+}
+
+content::WebContents* GuestViewManager::CreateGuestWithWebContentsParams(
+    const std::string& view_type,
+    content::WebContents* owner_web_contents,
+    const content::WebContents::CreateParams& create_params) {
+  auto guest = CreateGuestInternal(owner_web_contents, view_type);
+  if (!guest)
+    return nullptr;
+  content::WebContents::CreateParams guest_create_params(create_params);
+  guest_create_params.guest_delegate = guest;
+  auto guest_web_contents = WebContents::Create(guest_create_params);
+  guest->InitWithWebContents(base::DictionaryValue(), guest_web_contents);
+  return guest_web_contents;
+}
+
+content::WebContents* GuestViewManager::GetGuestByInstanceID(
+    int owner_process_id,
+    int element_instance_id) {
+  int guest_instance_id = GetGuestInstanceIDForElementID(owner_process_id,
+                                                         element_instance_id);
+  if (guest_instance_id == kInstanceIDNone)
+    return nullptr;
+
+  return GetGuestByInstanceID(guest_instance_id);
+}
+
+int GuestViewManager::GetGuestInstanceIDForElementID(int owner_process_id,
+                                                     int element_instance_id) {
+  auto iter = instance_id_map_.find(
+      ElementInstanceKey(owner_process_id, element_instance_id));
+  if (iter == instance_id_map_.end())
+    return kInstanceIDNone;
+  return iter->second;
+}
+
+SiteInstance* GuestViewManager::GetGuestSiteInstance(
+    const GURL& guest_site) {
+  for (const auto& guest : guest_web_contents_by_instance_id_) {
+    if (guest.second->GetSiteInstance()->GetSiteURL() == guest_site)
+      return guest.second->GetSiteInstance();
+  }
+  return nullptr;
+}
+
+bool GuestViewManager::ForEachGuest(WebContents* owner_web_contents,
+                                    const GuestCallback& callback) {
+  for (const auto& guest : guest_web_contents_by_instance_id_) {
+    auto guest_view = GuestViewBase::FromWebContents(guest.second);
+    if (guest_view->owner_web_contents() != owner_web_contents)
+      continue;
+
+    if (callback.Run(guest_view->web_contents()))
+      return true;
+  }
+  return false;
+}
+
+WebContents* GuestViewManager::GetFullPageGuest(
+    WebContents* embedder_web_contents) {
+  WebContents* result = nullptr;
+  ForEachGuest(embedder_web_contents,
+               base::Bind(&GuestViewManager::GetFullPageGuestHelper, &result));
+  return result;
+}
+
+void GuestViewManager::AddGuest(int guest_instance_id,
+                                WebContents* guest_web_contents) {
+  CHECK(!ContainsKey(guest_web_contents_by_instance_id_, guest_instance_id));
+  CHECK(CanUseGuestInstanceID(guest_instance_id));
+  guest_web_contents_by_instance_id_[guest_instance_id] = guest_web_contents;
+}
+
+void GuestViewManager::RemoveGuest(int guest_instance_id) {
+  auto it = guest_web_contents_by_instance_id_.find(guest_instance_id);
+  DCHECK(it != guest_web_contents_by_instance_id_.end());
+  guest_web_contents_by_instance_id_.erase(it);
+
+  auto id_iter = reverse_instance_id_map_.find(guest_instance_id);
+  if (id_iter != reverse_instance_id_map_.end()) {
+    const ElementInstanceKey& instance_id_key = id_iter->second;
+    instance_id_map_.erase(instance_id_map_.find(instance_id_key));
+    reverse_instance_id_map_.erase(id_iter);
+  }
+
+  // All the instance IDs that lie within [0, last_instance_id_removed_]
+  // are invalid.
+  // The remaining sparse invalid IDs are kept in |removed_instance_ids_| set.
+  // The following code compacts the set by incrementing
+  // |last_instance_id_removed_|.
+  if (guest_instance_id == last_instance_id_removed_ + 1) {
+    ++last_instance_id_removed_;
+    // Compact.
+    auto iter = removed_instance_ids_.begin();
+    while (iter != removed_instance_ids_.end()) {
+      int instance_id = *iter;
+      // The sparse invalid IDs must not lie within
+      // [0, last_instance_id_removed_]
+      DCHECK(instance_id > last_instance_id_removed_);
+      if (instance_id != last_instance_id_removed_ + 1)
+        break;
+      ++last_instance_id_removed_;
+      removed_instance_ids_.erase(iter++);
+    }
+  } else {
+    removed_instance_ids_.insert(guest_instance_id);
+  }
+}
+
+GuestViewBase* GuestViewManager::CreateGuestInternal(
+    content::WebContents* owner_web_contents,
+    const std::string& view_type) {
+  if (guest_view_registry_.empty())
+    RegisterGuestViewTypes();
+
+  auto it = guest_view_registry_.find(view_type);
+  if (it == guest_view_registry_.end()) {
+    NOTREACHED();
+    return nullptr;
+  }
+
+  return it->second.Run(owner_web_contents);
+}
+
+void GuestViewManager::RegisterGuestViewTypes() {
+  delegate_->RegisterAdditionalGuestViewTypes();
+}
+
+bool GuestViewManager::IsGuestAvailableToContext(GuestViewBase* guest) {
+  return delegate_->IsGuestAvailableToContext(guest);
+}
+
+void GuestViewManager::DispatchEvent(const std::string& event_name,
+                                     scoped_ptr<base::DictionaryValue> args,
+                                     GuestViewBase* guest,
+                                     int instance_id) {
+  // TODO(fsamuel): GuestViewManager should probably do something more useful
+  // here like log an error if the event could not be dispatched.
+  delegate_->DispatchEvent(event_name, args.Pass(), guest, instance_id);
+}
+
+content::WebContents* GuestViewManager::GetGuestByInstanceID(
+    int guest_instance_id) {
+  auto it = guest_web_contents_by_instance_id_.find(guest_instance_id);
+  if (it == guest_web_contents_by_instance_id_.end())
+    return nullptr;
+  return it->second;
+}
+
+bool GuestViewManager::CanEmbedderAccessInstanceIDMaybeKill(
+    int embedder_render_process_id,
+    int guest_instance_id) {
+  if (!CanEmbedderAccessInstanceID(embedder_render_process_id,
+                                   guest_instance_id)) {
+    // The embedder process is trying to access a guest it does not own.
+    content::RecordAction(
+        base::UserMetricsAction("BadMessageTerminate_BPGM"));
+    content::RenderProcessHost::FromID(embedder_render_process_id)
+        ->Shutdown(content::RESULT_CODE_KILLED_BAD_MESSAGE, false);
+    return false;
+  }
+  return true;
+}
+
+bool GuestViewManager::CanUseGuestInstanceID(int guest_instance_id) {
+  if (guest_instance_id <= last_instance_id_removed_)
+    return false;
+  return !ContainsKey(removed_instance_ids_, guest_instance_id);
+}
+
+// static
+bool GuestViewManager::GetFullPageGuestHelper(
+    content::WebContents** result,
+    content::WebContents* guest_web_contents) {
+  auto guest_view = GuestViewBase::FromWebContents(guest_web_contents);
+  if (guest_view && guest_view->is_full_page_plugin()) {
+    *result = guest_web_contents;
+    return true;
+  }
+  return false;
+}
+
+bool GuestViewManager::CanEmbedderAccessInstanceID(
+    int embedder_render_process_id,
+    int guest_instance_id) {
+  // The embedder is trying to access a guest with a negative or zero
+  // instance ID.
+  if (guest_instance_id <= kInstanceIDNone)
+    return false;
+
+  // The embedder is trying to access an instance ID that has not yet been
+  // allocated by GuestViewManager. This could cause instance ID
+  // collisions in the future, and potentially give one embedder access to a
+  // guest it does not own.
+  if (guest_instance_id > current_instance_id_)
+    return false;
+
+  // We might get some late arriving messages at tear down. Let's let the
+  // embedder tear down in peace.
+  auto it = guest_web_contents_by_instance_id_.find(guest_instance_id);
+  if (it == guest_web_contents_by_instance_id_.end())
+    return true;
+
+  auto guest_view = GuestViewBase::FromWebContents(it->second);
+  if (!guest_view)
+    return false;
+
+  return embedder_render_process_id ==
+      guest_view->owner_web_contents()->GetRenderProcessHost()->GetID();
+}
+
+GuestViewManager::ElementInstanceKey::ElementInstanceKey()
+    : embedder_process_id(content::ChildProcessHost::kInvalidUniqueID),
+      element_instance_id(content::ChildProcessHost::kInvalidUniqueID) {
+}
+
+GuestViewManager::ElementInstanceKey::ElementInstanceKey(
+    int embedder_process_id,
+    int element_instance_id)
+    : embedder_process_id(embedder_process_id),
+      element_instance_id(element_instance_id) {
+}
+
+bool GuestViewManager::ElementInstanceKey::operator<(
+    const GuestViewManager::ElementInstanceKey& other) const {
+  if (embedder_process_id != other.embedder_process_id)
+    return embedder_process_id < other.embedder_process_id;
+
+  return element_instance_id < other.element_instance_id;
+}
+
+bool GuestViewManager::ElementInstanceKey::operator==(
+    const GuestViewManager::ElementInstanceKey& other) const {
+  return (embedder_process_id == other.embedder_process_id) &&
+    (element_instance_id == other.element_instance_id);
+}
+
+}  // namespace guest_view
diff --git a/components/guest_view/browser/guest_view_manager.h b/components/guest_view/browser/guest_view_manager.h
new file mode 100644
index 0000000..f51d0a6
--- /dev/null
+++ b/components/guest_view/browser/guest_view_manager.h
@@ -0,0 +1,212 @@
+// 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 COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_H_
+#define COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_H_
+
+#include <map>
+
+#include "base/bind.h"
+#include "base/gtest_prod_util.h"
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "content/public/browser/browser_plugin_guest_manager.h"
+#include "content/public/browser/site_instance.h"
+#include "content/public/browser/web_contents.h"
+
+class GURL;
+
+namespace content {
+class BrowserContext;
+class WebContents;
+}  // namespace content
+
+namespace guest_view {
+
+class GuestViewBase;
+class GuestViewManagerDelegate;
+class GuestViewManagerFactory;
+
+class GuestViewManager : public content::BrowserPluginGuestManager,
+                         public base::SupportsUserData::Data {
+ public:
+  GuestViewManager(content::BrowserContext* context,
+                   scoped_ptr<GuestViewManagerDelegate> delegate);
+  ~GuestViewManager() override;
+
+  // Returns the GuestViewManager associated with |context|. If one isn't
+  // available, then it is created and returned.
+  static GuestViewManager* CreateWithDelegate(
+      content::BrowserContext* context,
+      scoped_ptr<GuestViewManagerDelegate> delegate);
+
+  // Returns the GuestViewManager associated with |context|. If one isn't
+  // available, then nullptr is returned.
+  static GuestViewManager* FromBrowserContext(content::BrowserContext* context);
+
+  // Overrides factory for testing. Default (NULL) value indicates regular
+  // (non-test) environment.
+  static void set_factory_for_testing(GuestViewManagerFactory* factory) {
+    GuestViewManager::factory_ = factory;
+  }
+  // Returns the guest WebContents associated with the given |guest_instance_id|
+  // if the provided |embedder_render_process_id| is allowed to access it.
+  // If the embedder is not allowed access, the embedder will be killed, and
+  // this method will return NULL. If no WebContents exists with the given
+  // instance ID, then NULL will also be returned.
+  content::WebContents* GetGuestByInstanceIDSafely(
+      int guest_instance_id,
+      int embedder_render_process_id);
+
+  // Associates the Browser Plugin with |element_instance_id| to a
+  // guest that has ID of |guest_instance_id| and sets initialization
+  // parameters, |params| for it.
+  void AttachGuest(int embedder_process_id,
+                   int element_instance_id,
+                   int guest_instance_id,
+                   const base::DictionaryValue& attach_params);
+
+  // Removes the association between |element_instance_id| and a guest instance
+  // ID if one exists.
+  void DetachGuest(GuestViewBase* guest);
+
+  // Indicates whether the |guest| is owned by an extension or Chrome App.
+  bool IsOwnedByExtension(GuestViewBase* guest);
+
+  int GetNextInstanceID();
+  int GetGuestInstanceIDForElementID(
+      int owner_process_id,
+      int element_instance_id);
+
+  template <typename T>
+  void RegisterGuestViewType() {
+    auto it = guest_view_registry_.find(T::Type);
+    DCHECK(it == guest_view_registry_.end());
+    guest_view_registry_[T::Type] = base::Bind(&T::Create);
+  }
+
+  using WebContentsCreatedCallback =
+      base::Callback<void(content::WebContents*)>;
+  void CreateGuest(const std::string& view_type,
+                   content::WebContents* owner_web_contents,
+                   const base::DictionaryValue& create_params,
+                   const WebContentsCreatedCallback& callback);
+
+  content::WebContents* CreateGuestWithWebContentsParams(
+      const std::string& view_type,
+      content::WebContents* owner_web_contents,
+      const content::WebContents::CreateParams& create_params);
+
+  content::SiteInstance* GetGuestSiteInstance(
+      const GURL& guest_site);
+
+  // BrowserPluginGuestManager implementation.
+  content::WebContents* GetGuestByInstanceID(
+      int owner_process_id,
+      int element_instance_id) override;
+  bool ForEachGuest(content::WebContents* owner_web_contents,
+                    const GuestCallback& callback) override;
+  content::WebContents* GetFullPageGuest(
+      content::WebContents* embedder_web_contents) override;
+
+ protected:
+  friend class GuestViewBase;
+  friend class GuestViewEvent;
+
+  // Can be overriden in tests.
+  virtual void AddGuest(int guest_instance_id,
+                        content::WebContents* guest_web_contents);
+
+  // Can be overriden in tests.
+  virtual void RemoveGuest(int guest_instance_id);
+
+  // Creates a guest of the provided |view_type|.
+  GuestViewBase* CreateGuestInternal(content::WebContents* owner_web_contents,
+                                     const std::string& view_type);
+
+  // Adds GuestView types to the GuestView registry.
+  void RegisterGuestViewTypes();
+
+  // Indicates whether the provided |guest| can be used in the context it has
+  // been created.
+  bool IsGuestAvailableToContext(GuestViewBase* guest);
+
+  // Dispatches the event with |name| with the provided |args| to the embedder
+  // of the given |guest| with |instance_id| for routing.
+  void DispatchEvent(const std::string& event_name,
+                     scoped_ptr<base::DictionaryValue> args,
+                     GuestViewBase* guest,
+                     int instance_id);
+
+  content::WebContents* GetGuestByInstanceID(int guest_instance_id);
+
+  bool CanEmbedderAccessInstanceIDMaybeKill(
+      int embedder_render_process_id,
+      int guest_instance_id);
+
+  bool CanEmbedderAccessInstanceID(int embedder_render_process_id,
+                                   int guest_instance_id);
+
+  // Returns true if |guest_instance_id| can be used to add a new guest to this
+  // manager.
+  // We disallow adding new guest with instance IDs that were previously removed
+  // from this manager using RemoveGuest.
+  bool CanUseGuestInstanceID(int guest_instance_id);
+
+  static bool GetFullPageGuestHelper(content::WebContents** result,
+                                     content::WebContents* guest_web_contents);
+
+  // Static factory instance (always NULL for non-test).
+  static GuestViewManagerFactory* factory_;
+
+  // Contains guests' WebContents, mapping from their instance ids.
+  using GuestInstanceMap = std::map<int, content::WebContents*>;
+  GuestInstanceMap guest_web_contents_by_instance_id_;
+
+  struct ElementInstanceKey {
+    int embedder_process_id;
+    int element_instance_id;
+
+    ElementInstanceKey();
+    ElementInstanceKey(int embedder_process_id,
+                       int element_instance_id);
+
+    bool operator<(const ElementInstanceKey& other) const;
+    bool operator==(const ElementInstanceKey& other) const;
+  };
+
+  using GuestInstanceIDMap = std::map<ElementInstanceKey, int>;
+  GuestInstanceIDMap instance_id_map_;
+
+  // The reverse map of GuestInstanceIDMap.
+  using GuestInstanceIDReverseMap = std::map<int, ElementInstanceKey>;
+  GuestInstanceIDReverseMap reverse_instance_id_map_;
+
+  using GuestCreationCallback =
+      base::Callback<GuestViewBase*(content::WebContents*)>;
+  using GuestViewCreationMap =
+      std::map<std::string, GuestViewManager::GuestCreationCallback>;
+  GuestViewCreationMap guest_view_registry_;
+
+  int current_instance_id_;
+
+  // Any instance ID whose number not greater than this was removed via
+  // RemoveGuest.
+  // This is used so that we don't have store all removed instance IDs in
+  // |removed_instance_ids_|.
+  int last_instance_id_removed_;
+  // The remaining instance IDs that are greater than
+  // |last_instance_id_removed_| are kept here.
+  std::set<int> removed_instance_ids_;
+
+  content::BrowserContext* context_;
+
+  scoped_ptr<GuestViewManagerDelegate> delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(GuestViewManager);
+};
+
+}  // namespace guest_view
+
+#endif  // COMPONETS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_H_
diff --git a/components/guest_view/browser/guest_view_manager_delegate.cc b/components/guest_view/browser/guest_view_manager_delegate.cc
new file mode 100644
index 0000000..244c516
--- /dev/null
+++ b/components/guest_view/browser/guest_view_manager_delegate.cc
@@ -0,0 +1,23 @@
+// Copyright 2015 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 "components/guest_view/browser/guest_view_manager_delegate.h"
+
+namespace guest_view {
+
+GuestViewManagerDelegate::GuestViewManagerDelegate() {
+}
+
+GuestViewManagerDelegate::~GuestViewManagerDelegate() {
+}
+
+bool GuestViewManagerDelegate::IsGuestAvailableToContext(GuestViewBase* guest) {
+  return false;
+}
+
+bool GuestViewManagerDelegate::IsOwnedByExtension(GuestViewBase* guest) {
+  return false;
+}
+
+}  // namespace guest
diff --git a/components/guest_view/browser/guest_view_manager_delegate.h b/components/guest_view/browser/guest_view_manager_delegate.h
new file mode 100644
index 0000000..a46c278d
--- /dev/null
+++ b/components/guest_view/browser/guest_view_manager_delegate.h
@@ -0,0 +1,53 @@
+// Copyright 2015 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 COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_DELEGATE_H_
+#define COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_DELEGATE_H_
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/values.h"
+
+namespace base {
+class DictionaryValue;
+}  // namespace base
+
+namespace guest_view {
+
+class GuestViewBase;
+
+// A GuestViewManagerDelegate interface allows GuestViewManager to delegate
+// responsibilities to other modules in Chromium. Different builds of Chromium
+// may use different GuestViewManagerDelegate implementations. For example,
+// mobile builds of Chromium do not include an extensions module and so
+// permission checks would be different, and IsOwnedByExtension would always
+// return false.
+class GuestViewManagerDelegate {
+ public:
+  GuestViewManagerDelegate();
+  virtual ~GuestViewManagerDelegate();
+
+  // Dispatches the event with |name| with the provided |args| to the embedder
+  // of the given |guest| with |instance_id| for routing.
+  virtual void DispatchEvent(const std::string& event_name,
+                             scoped_ptr<base::DictionaryValue> args,
+                             GuestViewBase* guest,
+                             int instance_id) {}
+
+  // Indicates whether the |guest| can be used within the context of where it
+  // was created.
+  virtual bool IsGuestAvailableToContext(GuestViewBase* guest);
+
+  // Indicates whether the |guest| is owned by an extension or Chrome App.
+  virtual bool IsOwnedByExtension(GuestViewBase* guest);
+
+  // Registers additional GuestView types the delegator (GuestViewManger) can
+  // create.
+  virtual void RegisterAdditionalGuestViewTypes() {}
+};
+
+}  // namespace guest_view
+
+#endif  // COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_DELEGATE_H_
diff --git a/components/guest_view/browser/guest_view_manager_factory.h b/components/guest_view/browser/guest_view_manager_factory.h
new file mode 100644
index 0000000..0d127a3
--- /dev/null
+++ b/components/guest_view/browser/guest_view_manager_factory.h
@@ -0,0 +1,30 @@
+// 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 COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_FACTORY_H_
+#define COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_FACTORY_H_
+
+namespace content {
+class BrowserContext;
+}
+
+namespace guest_view {
+
+class GuestViewManager;
+class GuestViewManagerDelegate;
+
+class GuestViewManagerFactory {
+ public:
+  virtual GuestViewManager* CreateGuestViewManager(
+      content::BrowserContext* context,
+      scoped_ptr<GuestViewManagerDelegate> delegate) = 0;
+
+ protected:
+  virtual ~GuestViewManagerFactory() {}
+};
+
+}  // namespace guest_view
+
+#endif  // COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MANAGER_FACTORY_H_
+
diff --git a/components/guest_view/browser/guest_view_manager_unittest.cc b/components/guest_view/browser/guest_view_manager_unittest.cc
new file mode 100644
index 0000000..1d43dbd
--- /dev/null
+++ b/components/guest_view/browser/guest_view_manager_unittest.cc
@@ -0,0 +1,84 @@
+// 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 "components/guest_view/browser/guest_view_manager.h"
+#include "components/guest_view/browser/guest_view_manager_delegate.h"
+#include "components/guest_view/browser/test_guest_view_manager.h"
+#include "content/public/test/test_browser_context.h"
+#include "content/public/test/test_renderer_host.h"
+#include "content/public/test/web_contents_tester.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using content::WebContents;
+using content::WebContentsTester;
+
+namespace guest_view {
+
+namespace {
+
+class GuestViewManagerTest : public content::RenderViewHostTestHarness {
+ public:
+  GuestViewManagerTest() {}
+  ~GuestViewManagerTest() override {}
+
+  scoped_ptr<WebContents> CreateWebContents() {
+    return scoped_ptr<WebContents>(
+        WebContentsTester::CreateTestWebContents(&browser_context_, NULL));
+  }
+
+ private:
+  content::TestBrowserContext browser_context_;
+
+  DISALLOW_COPY_AND_ASSIGN(GuestViewManagerTest);
+};
+
+}  // namespace
+
+TEST_F(GuestViewManagerTest, AddRemove) {
+  content::TestBrowserContext browser_context;
+  scoped_ptr<GuestViewManagerDelegate> delegate(
+      new GuestViewManagerDelegate());
+  scoped_ptr<TestGuestViewManager> manager(
+      new TestGuestViewManager(&browser_context, delegate.Pass()));
+
+  scoped_ptr<WebContents> web_contents1(CreateWebContents());
+  scoped_ptr<WebContents> web_contents2(CreateWebContents());
+  scoped_ptr<WebContents> web_contents3(CreateWebContents());
+
+  EXPECT_EQ(0, manager->last_instance_id_removed());
+
+  EXPECT_TRUE(manager->CanUseGuestInstanceID(1));
+  EXPECT_TRUE(manager->CanUseGuestInstanceID(2));
+  EXPECT_TRUE(manager->CanUseGuestInstanceID(3));
+
+  manager->AddGuest(1, web_contents1.get());
+  manager->AddGuest(2, web_contents2.get());
+  manager->RemoveGuest(2);
+
+  // Since we removed 2, it would be an invalid ID.
+  EXPECT_TRUE(manager->CanUseGuestInstanceID(1));
+  EXPECT_FALSE(manager->CanUseGuestInstanceID(2));
+  EXPECT_TRUE(manager->CanUseGuestInstanceID(3));
+
+  EXPECT_EQ(0, manager->last_instance_id_removed());
+
+  EXPECT_TRUE(manager->CanUseGuestInstanceID(3));
+
+  manager->AddGuest(3, web_contents3.get());
+  manager->RemoveGuest(1);
+  EXPECT_FALSE(manager->CanUseGuestInstanceID(1));
+  EXPECT_FALSE(manager->CanUseGuestInstanceID(2));
+
+  EXPECT_EQ(2, manager->last_instance_id_removed());
+  manager->RemoveGuest(3);
+  EXPECT_EQ(3, manager->last_instance_id_removed());
+
+  EXPECT_FALSE(manager->CanUseGuestInstanceID(1));
+  EXPECT_FALSE(manager->CanUseGuestInstanceID(2));
+  EXPECT_FALSE(manager->CanUseGuestInstanceID(3));
+
+  EXPECT_EQ(0u, manager->GetNumRemovedInstanceIDs());
+}
+
+}  // namespace guest_view
diff --git a/components/guest_view/browser/guest_view_message_filter.cc b/components/guest_view/browser/guest_view_message_filter.cc
new file mode 100644
index 0000000..d313f53
--- /dev/null
+++ b/components/guest_view/browser/guest_view_message_filter.cc
@@ -0,0 +1,80 @@
+// Copyright 2015 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 "components/guest_view/browser/guest_view_message_filter.h"
+
+#include "components/guest_view/browser/guest_view_base.h"
+#include "components/guest_view/browser/guest_view_manager.h"
+#include "components/guest_view/common/guest_view_messages.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
+#include "ipc/ipc_message_macros.h"
+
+using content::BrowserContext;
+using content::BrowserThread;
+using content::RenderFrameHost;
+using content::WebContents;
+
+namespace guest_view {
+
+GuestViewMessageFilter::GuestViewMessageFilter(int render_process_id,
+                                               BrowserContext* context)
+    : BrowserMessageFilter(GuestViewMsgStart),
+      render_process_id_(render_process_id),
+      browser_context_(context),
+      weak_ptr_factory_(this) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+}
+
+GuestViewMessageFilter::~GuestViewMessageFilter() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+}
+
+void GuestViewMessageFilter::OverrideThreadForMessage(
+    const IPC::Message& message,
+    BrowserThread::ID* thread) {
+  switch (message.type()) {
+    case GuestViewHostMsg_AttachGuest::ID:
+      *thread = BrowserThread::UI;
+      break;
+    default:
+      break;
+  }
+}
+
+void GuestViewMessageFilter::OnDestruct() const {
+  // Destroy the filter on the IO thread since that's where its weak pointers
+  // are being used.
+  BrowserThread::DeleteOnIOThread::Destruct(this);
+}
+
+bool GuestViewMessageFilter::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(GuestViewMessageFilter, message)
+    IPC_MESSAGE_HANDLER(GuestViewHostMsg_AttachGuest, OnAttachGuest)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void GuestViewMessageFilter::OnAttachGuest(
+    int element_instance_id,
+    int guest_instance_id,
+    const base::DictionaryValue& params) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  auto manager = GuestViewManager::FromBrowserContext(browser_context_);
+  // We should have a GuestViewManager at this point. If we don't then the
+  // embedder is misbehaving.
+  if (!manager)
+    return;
+
+  manager->AttachGuest(render_process_id_,
+                       element_instance_id,
+                       guest_instance_id,
+                       params);
+}
+
+}  // namespace guest_view
diff --git a/components/guest_view/browser/guest_view_message_filter.h b/components/guest_view/browser/guest_view_message_filter.h
new file mode 100644
index 0000000..7d2448f
--- /dev/null
+++ b/components/guest_view/browser/guest_view_message_filter.h
@@ -0,0 +1,67 @@
+// Copyright 2015 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 COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MESSAGE_FILTER_H_
+#define COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MESSAGE_FILTER_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "content/public/browser/browser_message_filter.h"
+
+namespace base {
+class DictionaryValue;
+}
+
+namespace content {
+class BrowserContext;
+class WebContents;
+}
+
+namespace gfx {
+class Size;
+}
+
+namespace guest_view {
+
+// This class filters out incoming GuestView-specific IPC messages from the
+// renderer process. It is created on the UI thread. Messages may be handled on
+// the IO thread or the UI thread.
+class GuestViewMessageFilter : public content::BrowserMessageFilter {
+ public:
+  GuestViewMessageFilter(int render_process_id,
+                         content::BrowserContext* context);
+
+ private:
+  friend class content::BrowserThread;
+  friend class base::DeleteHelper<GuestViewMessageFilter>;
+
+  ~GuestViewMessageFilter() override;
+
+  // content::BrowserMessageFilter implementation.
+  void OverrideThreadForMessage(const IPC::Message& message,
+                                content::BrowserThread::ID* thread) override;
+  void OnDestruct() const override;
+  bool OnMessageReceived(const IPC::Message& message) override;
+
+  // Message handlers on the UI thread.
+  void OnAttachGuest(int element_instance_id,
+                     int guest_instance_id,
+                     const base::DictionaryValue& attach_params);
+
+  const int render_process_id_;
+
+  // Should only be accessed on the UI thread.
+  content::BrowserContext* const browser_context_;
+
+  // Weak pointers produced by this factory are bound to the IO thread.
+  base::WeakPtrFactory<GuestViewMessageFilter> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GuestViewMessageFilter);
+};
+
+}  // namespace guest_view
+
+#endif  // COMPONENTS_GUEST_VIEW_BROWSER_GUEST_VIEW_MESSAGE_FILTER_H_
diff --git a/components/guest_view/browser/test_guest_view_manager.cc b/components/guest_view/browser/test_guest_view_manager.cc
new file mode 100644
index 0000000..90a1023
--- /dev/null
+++ b/components/guest_view/browser/test_guest_view_manager.cc
@@ -0,0 +1,99 @@
+// 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 "components/guest_view/browser/test_guest_view_manager.h"
+
+#include "base/memory/scoped_ptr.h"
+#include "components/guest_view/browser/guest_view_manager_delegate.h"
+
+namespace guest_view {
+
+TestGuestViewManager::TestGuestViewManager(
+    content::BrowserContext* context,
+    scoped_ptr<GuestViewManagerDelegate> delegate)
+    : GuestViewManager(context, delegate.Pass()),
+      num_guests_created_(0) {
+}
+
+TestGuestViewManager::~TestGuestViewManager() {
+}
+
+size_t TestGuestViewManager::GetNumGuestsActive() const {
+  return guest_web_contents_by_instance_id_.size();
+}
+
+size_t TestGuestViewManager::GetNumRemovedInstanceIDs() const {
+  return removed_instance_ids_.size();
+}
+
+content::WebContents* TestGuestViewManager::GetLastGuestCreated() {
+  content::WebContents* web_contents = nullptr;
+  for (int i = current_instance_id_; i >= 0; i--) {
+    web_contents = GetGuestByInstanceID(i);
+    if (web_contents) {
+      break;
+    }
+  }
+  return web_contents;
+}
+
+void TestGuestViewManager::WaitForAllGuestsDeleted() {
+  // Make sure that every guest that was created have been removed.
+  for (auto& watcher : guest_web_contents_watchers_)
+    watcher->Wait();
+}
+
+void TestGuestViewManager::WaitForGuestCreated() {
+  created_message_loop_runner_ = new content::MessageLoopRunner;
+  created_message_loop_runner_->Run();
+}
+
+content::WebContents* TestGuestViewManager::WaitForSingleGuestCreated() {
+  if (!GetNumGuestsActive()) {
+    // Guests have been created and subsequently destroyed.
+    if (num_guests_created() > 0)
+      return nullptr;
+    WaitForGuestCreated();
+  }
+
+  return GetLastGuestCreated();
+}
+
+void TestGuestViewManager::AddGuest(int guest_instance_id,
+                                    content::WebContents* guest_web_contents) {
+  GuestViewManager::AddGuest(guest_instance_id, guest_web_contents);
+
+  guest_web_contents_watchers_.push_back(
+      linked_ptr<content::WebContentsDestroyedWatcher>(
+          new content::WebContentsDestroyedWatcher(guest_web_contents)));
+
+  ++num_guests_created_;
+
+  if (created_message_loop_runner_.get())
+    created_message_loop_runner_->Quit();
+}
+
+void TestGuestViewManager::RemoveGuest(int guest_instance_id) {
+  GuestViewManager::RemoveGuest(guest_instance_id);
+}
+
+// Test factory for creating test instances of GuestViewManager.
+TestGuestViewManagerFactory::TestGuestViewManagerFactory()
+    : test_guest_view_manager_(NULL) {
+}
+
+TestGuestViewManagerFactory::~TestGuestViewManagerFactory() {
+}
+
+GuestViewManager* TestGuestViewManagerFactory::CreateGuestViewManager(
+    content::BrowserContext* context,
+    scoped_ptr<GuestViewManagerDelegate> delegate) {
+  if (!test_guest_view_manager_) {
+    test_guest_view_manager_ =
+        new TestGuestViewManager(context, delegate.Pass());
+  }
+  return test_guest_view_manager_;
+}
+
+}  // namespace guest_view
diff --git a/components/guest_view/browser/test_guest_view_manager.h b/components/guest_view/browser/test_guest_view_manager.h
new file mode 100644
index 0000000..cbf942f
--- /dev/null
+++ b/components/guest_view/browser/test_guest_view_manager.h
@@ -0,0 +1,82 @@
+// 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 COMPONENTS_GUEST_VIEW_BROWSER_TEST_GUEST_VIEW_MANAGER_H_
+#define COMPONENTS_GUEST_VIEW_BROWSER_TEST_GUEST_VIEW_MANAGER_H_
+
+#include "base/memory/linked_ptr.h"
+#include "components/guest_view/browser/guest_view_manager.h"
+#include "components/guest_view/browser/guest_view_manager_factory.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/test_utils.h"
+
+namespace guest_view {
+
+class TestGuestViewManager : public GuestViewManager {
+ public:
+  TestGuestViewManager(
+      content::BrowserContext* context,
+      scoped_ptr<GuestViewManagerDelegate> delegate);
+  ~TestGuestViewManager() override;
+
+  void WaitForAllGuestsDeleted();
+  content::WebContents* WaitForSingleGuestCreated();
+
+  content::WebContents* GetLastGuestCreated();
+
+  // Returns the number of guests currently still alive at the time of calling
+  // this method.
+  size_t GetNumGuestsActive() const;
+
+  // Returns the size of the set of removed instance IDs.
+  size_t GetNumRemovedInstanceIDs() const;
+
+  // Returns the number of guests that have been created since the creation of
+  // this GuestViewManager.
+  int num_guests_created() const { return num_guests_created_; }
+
+  // Returns the last guest instance ID removed from the manager.
+  int last_instance_id_removed() const { return last_instance_id_removed_; }
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(GuestViewManagerTest, AddRemove);
+
+  // GuestViewManager override:
+  void AddGuest(int guest_instance_id,
+                content::WebContents* guest_web_contents) override;
+  void RemoveGuest(int guest_instance_id) override;
+
+  void WaitForGuestCreated();
+
+  using GuestViewManager::last_instance_id_removed_;
+  using GuestViewManager::removed_instance_ids_;
+
+  int num_guests_created_;
+
+  std::vector<linked_ptr<content::WebContentsDestroyedWatcher>>
+      guest_web_contents_watchers_;
+  scoped_refptr<content::MessageLoopRunner> created_message_loop_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestGuestViewManager);
+};
+
+// Test factory for creating test instances of GuestViewManager.
+class TestGuestViewManagerFactory : public GuestViewManagerFactory {
+ public:
+  TestGuestViewManagerFactory();
+  ~TestGuestViewManagerFactory() override;
+
+  GuestViewManager* CreateGuestViewManager(
+      content::BrowserContext* context,
+      scoped_ptr<GuestViewManagerDelegate> delegate) override;
+
+ private:
+  TestGuestViewManager* test_guest_view_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestGuestViewManagerFactory);
+};
+
+}  // namespace guest_view
+
+#endif  // COMPONENTS_GUEST_VIEW_BROWSER_TEST_GUEST_VIEW_MANAGER_H_
diff --git a/components/guest_view/common/DEPS b/components/guest_view/common/DEPS
new file mode 100644
index 0000000..b0e64bf
--- /dev/null
+++ b/components/guest_view/common/DEPS
@@ -0,0 +1,3 @@
+include_rules = [
+  "+ipc"
+]
diff --git a/components/guest_view/common/OWNERS b/components/guest_view/common/OWNERS
new file mode 100644
index 0000000..bba0da4
--- /dev/null
+++ b/components/guest_view/common/OWNERS
@@ -0,0 +1,15 @@
+fsamuel@chromium.org
+lazyboy@chromium.org
+
+# For security review of IPC message files.
+per-file *_messages*.h=set noparent
+per-file *_messages*.h=dcheng@chromium.org
+per-file *_messages*.h=inferno@chromium.org
+per-file *_messages*.h=jln@chromium.org
+per-file *_messages*.h=jschuh@chromium.org
+per-file *_messages*.h=kenrb@chromium.org
+per-file *_messages*.h=mkwst@chromium.org
+per-file *_messages*.h=nasko@chromium.org
+per-file *_messages*.h=palmer@chromium.org
+per-file *_messages*.h=tsepez@chromium.org
+per-file *_messages*.h=wfh@chromium.org
diff --git a/components/guest_view/common/guest_view_constants.cc b/components/guest_view/common/guest_view_constants.cc
new file mode 100644
index 0000000..e68c3b8
--- /dev/null
+++ b/components/guest_view/common/guest_view_constants.cc
@@ -0,0 +1,45 @@
+// 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 "components/guest_view/common/guest_view_constants.h"
+
+namespace guest_view {
+
+// Sizing attributes/parameters.
+const char kAttributeAutoSize[] = "autosize";
+const char kAttributeMaxHeight[] = "maxheight";
+const char kAttributeMaxWidth[] = "maxwidth";
+const char kAttributeMinHeight[] = "minheight";
+const char kAttributeMinWidth[] = "minwidth";
+const char kElementWidth[] = "elementWidth";
+const char kElementHeight[] = "elementHeight";
+const char kElementSizeIsLogical[] = "elementSizeIsLogical";
+
+// Events.
+const char kEventResize[] = "guestViewInternal.onResize";
+
+// Parameters/properties on events.
+const char kCode[] = "code";
+const char kContentWindowID[] = "contentWindowId";
+const char kID[] = "id";
+const char kIsTopLevel[] = "isTopLevel";
+const char kNewWidth[] = "newWidth";
+const char kNewHeight[] = "newHeight";
+const char kOldWidth[] = "oldWidth";
+const char kOldHeight[] = "oldHeight";
+const char kReason[] = "reason";
+const char kUrl[] = "url";
+const char kUserGesture[] = "userGesture";
+
+// Initialization parameters.
+const char kParameterApi[] = "api";
+const char kParameterInstanceId[] = "instanceId";
+
+// Other.
+const char kGuestViewManagerKeyName[] = "guest_view_manager";
+const int kInstanceIDNone = 0;
+const int kDefaultWidth = 300;
+const int kDefaultHeight = 300;
+
+}  // namespace guestview
diff --git a/components/guest_view/common/guest_view_constants.h b/components/guest_view/common/guest_view_constants.h
new file mode 100644
index 0000000..ef9066e
--- /dev/null
+++ b/components/guest_view/common/guest_view_constants.h
@@ -0,0 +1,50 @@
+// 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.
+
+// Constants used for the WebView API.
+
+#ifndef COMPONENTS_GUEST_VIEW_COMMON_GUEST_VIEW_CONSTANTS_H_
+#define COMPONENTS_GUEST_VIEW_COMMON_GUEST_VIEW_CONSTANTS_H_
+
+namespace guest_view {
+
+// Sizing attributes/parameters.
+extern const char kAttributeAutoSize[];
+extern const char kAttributeMaxHeight[];
+extern const char kAttributeMaxWidth[];
+extern const char kAttributeMinHeight[];
+extern const char kAttributeMinWidth[];
+extern const char kElementWidth[];
+extern const char kElementHeight[];
+extern const char kElementSizeIsLogical[];
+
+// Events.
+extern const char kEventResize[];
+
+// Parameters/properties on events.
+extern const char kCode[];
+extern const char kContentWindowID[];
+extern const char kID[];
+extern const char kIsTopLevel[];
+extern const char kNewWidth[];
+extern const char kNewHeight[];
+extern const char kOldWidth[];
+extern const char kOldHeight[];
+extern const char kReason[];
+extern const char kUrl[];
+extern const char kUserGesture[];
+
+// Initialization parameters.
+extern const char kParameterApi[];
+extern const char kParameterInstanceId[];
+
+// Other.
+extern const char kGuestViewManagerKeyName[];
+extern const int kInstanceIDNone;
+extern const int kDefaultWidth;
+extern const int kDefaultHeight;
+
+}  // namespace guest_view
+
+#endif  // COMPONENTS_GUEST_VIEW_COMMON_GUEST_VIEW_CONSTANTS_H_
diff --git a/components/guest_view/common/guest_view_message_generator.cc b/components/guest_view/common/guest_view_message_generator.cc
new file mode 100644
index 0000000..6a0bca1
--- /dev/null
+++ b/components/guest_view/common/guest_view_message_generator.cc
@@ -0,0 +1,33 @@
+// Copyright 2015 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.
+
+// Get basic type definitions.
+#define IPC_MESSAGE_IMPL
+#include "components/guest_view/common/guest_view_message_generator.h"
+
+// Generate constructors.
+#include "ipc/struct_constructor_macros.h"
+#include "components/guest_view/common/guest_view_message_generator.h"
+
+// Generate destructors.
+#include "ipc/struct_destructor_macros.h"
+#include "components/guest_view/common/guest_view_message_generator.h"
+
+// Generate param traits write methods.
+#include "ipc/param_traits_write_macros.h"
+namespace IPC {
+#include "components/guest_view/common/guest_view_message_generator.h"
+}  // namespace IPC
+
+// Generate param traits read methods.
+#include "ipc/param_traits_read_macros.h"
+namespace IPC {
+#include "components/guest_view/common/guest_view_message_generator.h"
+}  // namespace IPC
+
+// Generate param traits log methods.
+#include "ipc/param_traits_log_macros.h"
+namespace IPC {
+#include "components/guest_view/common/guest_view_message_generator.h"
+}  // namespace IPC
diff --git a/components/guest_view/common/guest_view_message_generator.h b/components/guest_view/common/guest_view_message_generator.h
new file mode 100644
index 0000000..0e569e2
--- /dev/null
+++ b/components/guest_view/common/guest_view_message_generator.h
@@ -0,0 +1,7 @@
+// Copyright 2015 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.
+
+// Multiply-included file, no traditional include guard.
+
+#include "components/guest_view/common/guest_view_messages.h"
diff --git a/components/guest_view/common/guest_view_messages.h b/components/guest_view/common/guest_view_messages.h
new file mode 100644
index 0000000..9772b6f
--- /dev/null
+++ b/components/guest_view/common/guest_view_messages.h
@@ -0,0 +1,35 @@
+// Copyright 2015 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.
+
+// IPC messages for GuestViews.
+// Multiply-included message file, hence no include guard.
+
+#include "base/values.h"
+#include "ipc/ipc_message_macros.h"
+
+#define IPC_MESSAGE_START GuestViewMsgStart
+
+// Messages sent from the browser to the renderer.
+
+// Once a RenderView proxy has been created for the guest in the embedder render
+// process, this IPC informs the embedder of the proxy's routing ID.
+IPC_MESSAGE_CONTROL2(GuestViewMsg_GuestAttached,
+                     int /* element_instance_id */,
+                     int /* source_routing_id */)
+
+// This IPC tells the browser process to detach the provided
+// |element_instance_id| from a GuestViewBase if it is attached to one.
+// In other words, routing of input and graphics will no longer flow through
+// the container associated with the provided ID.
+IPC_MESSAGE_CONTROL1(GuestViewMsg_GuestDetached,
+                     int /* element_instance_id*/)
+
+// Messages sent from the renderer to the browser.
+
+// Sent by the renderer to set initialization parameters of a Browser Plugin
+// that is identified by |element_instance_id|.
+IPC_MESSAGE_CONTROL3(GuestViewHostMsg_AttachGuest,
+                     int /* element_instance_id */,
+                     int /* guest_instance_id */,
+                     base::DictionaryValue /* attach_params */)