Browser Plugin: New Implementation (Browser Side)

content/browser/browser_plugin/browser_plugin_host.cc

+// Copyright (c) 2012 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 "content/browser/browser_plugin/browser_plugin_host.h"
+
+#include "base/utf_string_conversions.h"
+#include "content/browser/browser_plugin/browser_plugin_host_helper.h"
+#include "content/browser/renderer_host/render_view_host_impl.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+#include "content/common/browser_plugin_messages.h"
+#include "content/common/view_messages.h"
+#include "content/port/browser/render_widget_host_view_port.h"
+#include "content/public/browser/notification_details.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_source.h"
+#include "content/public/browser/notification_types.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_widget_host_view.h"
+#include "content/public/browser/site_instance.h"
+#include "content/public/browser/web_contents_view.h"
+#include "content/public/common/result_codes.h"
+#include "content/public/common/url_constants.h"
+
+namespace content {
+
+namespace {
+const int kGuestHangTimeout = 5000;
+}
+
+BrowserPluginHost::BrowserPluginHost(
+    WebContentsImpl* web_contents)
+    : WebContentsObserver(web_contents),
+      embedder_render_process_host_(NULL),
+      instance_id_(0),
+      damage_buffer_(NULL),
+      pending_update_counter_(0) {
+  // Listen to visibility changes so that an embedder hides its guests
+  // as well.
+  registrar_.Add(this,
+                 NOTIFICATION_WEB_CONTENTS_VISIBILITY_CHANGED,
+                 Source<WebContents>(web_contents));
+  // Construct plumbing helpers when a new RenderViewHost is created for
+  // this BrowserPluginHost's WebContentsImpl.
+  registrar_.Add(this,
+                 NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED,
+                 Source<WebContents>(web_contents));
+}
+
+BrowserPluginHost::~BrowserPluginHost() {
+  if (damage_buffer_)
+    delete damage_buffer_;
+}
+
+BrowserPluginHost* BrowserPluginHost::GetGuestByInstanceID(
+    int container_id) const {
+  ContainerInstanceMap::const_iterator it =
+      guests_by_instance_id_.find(container_id);
+  if (it != guests_by_instance_id_.end())
+    return it->second;
+  return NULL;
+}
+
+void BrowserPluginHost::AddGuest(int instance_id,
+                                 BrowserPluginHost* guest,
+                                 int64 frame_id) {
+  DCHECK(guests_by_instance_id_.find(instance_id) ==
+      guests_by_instance_id_.end());
+  guests_by_instance_id_[instance_id] = guest;
+  guests_[guest->web_contents()] = frame_id;
+}
+
+bool BrowserPluginHost::TakeFocus(bool reverse) {
+  embedder_render_process_host()->Send(
+      new BrowserPluginMsg_AdvanceFocus(instance_id(), reverse));
+  return true;
+}
+
+void BrowserPluginHost::RendererUnresponsive(WebContents* source) {
+  base::ProcessHandle process_handle =
+      web_contents()->GetRenderProcessHost()->GetHandle();
+  base::KillProcess(process_handle, RESULT_CODE_HUNG, false);

[Charlie Reis, 2012/08/13 17:50:14]

I don't think we want to kill an unresponsive renderer.  This is a very common
event on heavily loaded clients (or cases like session restore), and there's
often a very good chance the renderer will finish what it's doing.  This is
going to result in a lot of kills.

Is there any other way to handle an unresponsive guest?

Also, this is another case where it's not clear whether this applies to just
guests or both embedders and guests.  We certainly wouldn't want to kill an
unresponsive embedder.

[Fady Samuel, 2012/08/13 21:30:08]

Discussed offline. For the time being this still needs to happen in the guest
because the guest can potentially hang the embedder on input events.

+}
+
+bool BrowserPluginHost::OnMessageReceived(const IPC::Message& message) {
+  return false;
+}
+
+void BrowserPluginHost::NavigateOrCreateGuest(
+    RenderViewHost* render_view_host,
+    int instance_id,
+    long long frame_id,

[Charlie Reis, 2012/08/13 17:50:14]

Most frame_ids in view_messages.h are int64.  Why is this a long long?

[Fady Samuel, 2012/08/13 21:30:08]

Done.

+    const std::string& src,
+    const gfx::Size& size) {
+  BrowserPluginHost* guest =
+      GetGuestByInstanceID(instance_id);
+  WebContentsImpl* guest_web_contents =
+      guest ?
+          static_cast<WebContentsImpl*>(guest->web_contents()): NULL;

[Charlie Reis, 2012/08/13 17:50:14]

This feels awkward.  Why not just set it to null here, and assign it to
guest->web_contents() in the else block of the if below?

+  GURL url(src);
+  if (!guest) {
+    std::string host = render_view_host->GetSiteInstance()->GetSite().host();
+    GURL guest_url(
+        base::StringPrintf("%s://%s", chrome::kGuestScheme, host.c_str()));

[Charlie Reis, 2012/08/13 17:50:14]

nit: guest_url -> guest_site

+    // The SiteInstance of a given guest is based on the fact that it's a guest
+    // in addition to which platform application the guest belongs to, rather
+    // than the URL that the guest is being navigated to.

[Charlie Reis, 2012/08/13 17:50:14]

nit: Please move this comment above the host declaration on line 102.

Also, it's unfortunate we don't have any way to enforce that this is in a
platform app.  Are there things that will break if someone tries to create a
BrowserPlugin elsewhere (e.g., in a WebUI page)?

Also, do we need things to enforce that these guest processes won't share across
apps if the process limit is reached?  (Is there already a bug on file for
this?)

+    SiteInstance* guest_site_instance =
+        SiteInstance::CreateForURL(web_contents()->GetBrowserContext(),
+        guest_url);

[Charlie Reis, 2012/08/13 17:50:14]

nit: Wrong indent (should be even with the first argument).

+    guest_web_contents =
+        static_cast<WebContentsImpl*>(
+            WebContents::Create(
+                web_contents()->GetBrowserContext(),
+                guest_site_instance,
+                MSG_ROUTING_NONE,
+                NULL, // base WebContents
+                NULL  // session storage namespace
+            ));
+    guest = guest_web_contents->browser_plugin_host();

[Charlie Reis, 2012/08/13 17:50:14]

I find it odd that all WebContents automatically have a BrowserPluginHost.  Only
a very small fraction of them will ever use it.

+    guest->set_embedder_render_process_host(
+        render_view_host->GetProcess());
+    guest->set_instance_id(instance_id);
+    guest_web_contents->GetMutableRendererPrefs()->
+        throttle_input_events = false;
+    AddGuest(instance_id, guest, frame_id);
+  }
+  guest->web_contents()->SetDelegate(guest);
+  guest->web_contents()->GetController().LoadURL(
+      url,
+      Referrer(),
+      PAGE_TRANSITION_AUTO_SUBFRAME,
+      std::string());
+  if (!size.IsEmpty())
+    guest_web_contents->GetView()->SizeContents(size);
+}
+
+void BrowserPluginHost::SetDamageBuffer(TransportDIB* damage_buffer,
+                                        const gfx::Size& size,
+                                        float scale_factor) {
+  if (damage_buffer_)
+    delete damage_buffer_;
+  damage_buffer_ = damage_buffer;
+  damage_buffer_size_ = size;
+  damage_buffer_scale_factor_ = scale_factor;
+}
+
+void BrowserPluginHost::ResizeGuest(int instance_id,
+                                    TransportDIB* damage_buffer,
+                                    int width, int height,
+                                    bool resize_pending,
+                                    float scale_factor) {
+  BrowserPluginHost* guest = GetGuestByInstanceID(instance_id);
+  if (!guest)
+    return;
+  WebContentsImpl* guest_web_contents =
+      guest ? static_cast<WebContentsImpl*>(guest->web_contents()): NULL;

[Charlie Reis, 2012/08/13 17:50:14]

nit: Space before :

+  guest->SetDamageBuffer(damage_buffer, gfx::Size(width, height), scale_factor);

[Charlie Reis, 2012/08/13 17:50:14]

Won't this crash if guest is null?  (You just null-checked it on the line
before.)

+  if (!resize_pending)
+    guest_web_contents->GetView()->SizeContents(gfx::Size(width, height));
+}
+
+void BrowserPluginHost::UpdateRect(
+    RenderViewHost* render_view_host,
+    const ViewHostMsg_UpdateRect_Params& params) {
+  // This handler is only of interest to us for the 2D software rendering path.
+  // needs_ack should always be true for the 2D path.
+  // TODO(fsamuel): Do we need to do something different in the 3D case?
+  if (!params.needs_ack)
+    return;
+
+  // Only copy damage if the guest's view size is equal to the damage buffer's
+  // size and the guest's scale factor is equal to the damage buffer's scale
+  // factor.
+  if (params.view_size.width() == damage_buffer_size().width() &&
+      params.view_size.height() == damage_buffer_size().height() &&
+      params.scale_factor == damage_buffer_scale_factor()) {
+    TransportDIB* dib = render_view_host->GetProcess()->
+        GetTransportDIB(params.bitmap);
+    if (dib) {
+      void* guest_memory = dib->memory();
+      void* embedder_memory = damage_buffer_->memory();
+      int size = std::min(dib->size(), damage_buffer_->size());
+      memcpy(embedder_memory, guest_memory, size);
+    }
+  }
+  DCHECK(embedder_render_process_host());
+  BrowserPluginMsg_UpdateRect_Params relay_params;
+  relay_params.bitmap_rect = params.bitmap_rect;
+  relay_params.dx = params.dx;
+  relay_params.dy = params.dy;
+  relay_params.scroll_rect = params.scroll_rect;
+  relay_params.copy_rects = params.copy_rects;
+  relay_params.view_size = params.view_size;
+  relay_params.scale_factor = params.scale_factor;
+  relay_params.is_resize_ack = ViewHostMsg_UpdateRect_Flags::is_resize_ack(
+      params.flags);
+
+  // We need to send the ACK to the same render_view_host that issued
+  // the UpdateRect. We keep track of this correspondence via a message_id.
+  int message_id = pending_update_counter_++;
+  pending_updates_.AddWithID(render_view_host, message_id);
+
+  gfx::Size param_size = gfx::Size(
+       params.view_size.width(),
+       params.view_size.height());
+   content::NotificationService::current()->Notify(
+       NOTIFICATION_BROWSER_PLUGIN_UPDATE_RECT,
+       content::Source<BrowserPluginHost>(this),
+       content::Details<const gfx::Size>(&param_size));
+
+  embedder_render_process_host()->Send(
+      new BrowserPluginMsg_UpdateRect(instance_id(),
+                                      message_id,
+                                      relay_params));
+}
+
+void BrowserPluginHost::UpdateRectACK(int message_id,
+                                      const gfx::Size& size) {
+  RenderViewHost* render_view_host = pending_updates_.Lookup(message_id);
+  // If the guest has crashed since it sent the initial ViewHostMsg_UpdateRect
+  // then the pending_updates_ map will have been cleared.
+  if (!render_view_host)
+    return;
+  pending_updates_.Remove(message_id);
+  render_view_host->Send(
+      new ViewMsg_UpdateRect_ACK(render_view_host->GetRoutingID()));
+  if (!size.IsEmpty())
+    render_view_host->GetView()->SetSize(size);
+}
+
+void BrowserPluginHost::HandleInputEvent(
+    RenderViewHost* render_view_host,
+    const gfx::Rect& guest_rect,
+    const WebKit::WebInputEvent& event,
+    IPC::Message* reply_message) {
+  guest_rect_ = guest_rect;
+  RenderViewHostImpl* guest_rvh = static_cast<RenderViewHostImpl*>(
+      web_contents()->GetRenderViewHost());
+  IPC::Message* message = new ViewMsg_HandleInputEvent(
+      guest_rvh->GetRoutingID());
+
+  // Copy the WebInputEvent and modify the event type. The guest expects
+  // WebInputEvent::RawKeyDowns and not KeyDowns.
+  scoped_array<char> input_buffer(new char[event.size]);
+  memcpy(input_buffer.get(), &event, event.size);
+  WebKit::WebInputEvent* input_event =
+      reinterpret_cast<WebKit::WebInputEvent*>(input_buffer.get());
+  if (event.type == WebKit::WebInputEvent::KeyDown)
+    input_event->type = WebKit::WebInputEvent::RawKeyDown;
+
+  message->WriteData(input_buffer.get(), event.size);
+  // TODO(fsamuel): What do we need to do here? This is for keyboard shortcuts.
+  if (input_event->type == WebKit::WebInputEvent::RawKeyDown)
+    message->WriteBool(false);
+  guest_rvh->Send(message);
+
+  DCHECK(!pending_input_event_reply_.get());
+  pending_input_event_reply_.reset(reply_message);
+  guest_rvh->StartHangMonitorTimeout(
+      base::TimeDelta::FromMilliseconds(kGuestHangTimeout));
+}
+
+void BrowserPluginHost::HandleInputEventAck(RenderViewHost* render_view_host,
+                                            bool handled) {
+  DCHECK(pending_input_event_reply_.get());
+  IPC::Message* reply_message = pending_input_event_reply_.release();
+  BrowserPluginHostMsg_HandleInputEvent::WriteReplyParams(reply_message,
+                                                          handled,
+                                                          cursor_);
+  embedder_render_process_host()->Send(reply_message);
+  RenderViewHostImpl* guest_rvh =
+      static_cast<RenderViewHostImpl*>(render_view_host);
+  guest_rvh->StopHangMonitorTimeout();
+}
+
+void BrowserPluginHost::SetFocus(bool focused) {
+  RenderViewHost* render_view_host = web_contents()->GetRenderViewHost();
+  render_view_host->Send(
+      new ViewMsg_SetFocus(render_view_host->GetRoutingID(), focused));
+}
+
+void BrowserPluginHost::ShowWidget(RenderViewHost* render_view_host,
+                                   int route_id,
+                                   const gfx::Rect& initial_pos) {
+  RenderWidgetHostView* popup_rwhv =
+      static_cast<WebContentsImpl*>(web_contents())->
+          GetCreatedWidget(route_id);
+
+  RenderWidgetHostViewPort* widget_host_view =
+      RenderWidgetHostViewPort::FromRWHV(popup_rwhv);
+  if (!widget_host_view)
+    return;
+  gfx::Rect screen_pos(initial_pos);
+  screen_pos.Offset(guest_rect_.origin());
+  widget_host_view->InitAsPopup(web_contents()->GetRenderWidgetHostView(),
+                                screen_pos);
+  RenderWidgetHostImpl* render_widget_host_impl =
+      RenderWidgetHostImpl::From(widget_host_view->GetRenderWidgetHost());
+  render_widget_host_impl->Init();
+  render_widget_host_impl->set_allow_privileged_mouse_lock(false);
+}
+
+void BrowserPluginHost::SetCursor(const WebCursor& cursor) {
+  cursor_ = cursor;
+}
+
+void BrowserPluginHost::DestroyGuests() {
+  for (GuestMap::const_iterator it = guests_.begin();
+       it != guests_.end(); ++it) {
+    WebContents* web_contents = it->first;
+    delete web_contents;
+  }
+  guests_.clear();
+  guests_by_instance_id_.clear();
+}
+
+void BrowserPluginHost::DestroyGuestByInstanceID(int instance_id) {
+

[Charlie Reis, 2012/08/13 17:50:14]

nit: No empty line.

+  BrowserPluginHost* guest = GetGuestByInstanceID(instance_id);
+  if (!guest)
+    return;
+  WebContents* guest_web_contents = guest->web_contents();
+  DCHECK(guest_web_contents);
+  delete guest_web_contents;
+
+  GuestMap::iterator guest_it = guests_.find(guest_web_contents);
+  DCHECK(guest_it != guests_.end());
+
+  guests_.erase(guest_it);
+  guests_by_instance_id_.erase(instance_id);
+}
+
+void BrowserPluginHost::DidCommitProvisionalLoadForFrame(
+    int64 frame_id,
+    bool is_main_frame,
+    const GURL& url,
+    PageTransition transition_type,
+    RenderViewHost* render_view_host) {
+  // Clean-up guests that lie in the frame that we're navigating.
+  typedef std::set<WebContents*> GuestSet;
+  GuestSet guests_to_delete;

[Charlie Reis, 2012/08/13 17:50:14]

This looks like it finds all the guests in the frame that navigated.  What about
the subframes of that frame?

e.g., Page A has subframe B, which itself has subframe C.  If B navigates, we
have to destroy any guests present in B or C.

+  for (GuestMap::const_iterator it = guests_.begin();
+       it != guests_.end(); ++it) {
+    WebContents* web_contents = it->first;
+    if (it->second == frame_id) {

[Charlie Reis, 2012/08/13 17:50:14]

nit: No braces needed for one-line if.

+      guests_to_delete.insert(web_contents);
+    }
+  }
+  for (GuestSet::const_iterator it = guests_to_delete.begin();
+       it != guests_to_delete.end(); ++it) {
+    int instance_id = static_cast<WebContentsImpl*>(*it)->
+        browser_plugin_host()->instance_id();
+    DestroyGuestByInstanceID(instance_id);
+  }
+  // If this is a guest, inform its embedder of the updated URL.
+  // TODO(creis, fsamuel): Ensure this is safe/secure.
+  if (is_main_frame && embedder_render_process_host()) {
+    embedder_render_process_host()->Send(
+        new BrowserPluginMsg_DidNavigate(instance_id(), url));
+  }
+}
+
+void BrowserPluginHost::RenderViewDeleted(RenderViewHost* render_view_host) {
+  DestroyGuests();
+}
+
+void BrowserPluginHost::RenderViewGone(base::TerminationStatus status) {
+  DestroyGuests();
+  if (embedder_render_process_host()) {
+    if (pending_input_event_reply_.get()) {
+      IPC::Message* reply_message = pending_input_event_reply_.release();
+      BrowserPluginHostMsg_HandleInputEvent::WriteReplyParams(reply_message,
+                                                              false,
+                                                              cursor_);
+      embedder_render_process_host()->Send(reply_message);
+    }
+    embedder_render_process_host()->Send(
+        new BrowserPluginMsg_GuestCrashed(instance_id()));
+    IDMap<RenderViewHost>::const_iterator iter(&pending_updates_);
+    while (!iter.IsAtEnd()) {
+      pending_updates_.Remove(iter.GetCurrentKey());
+      iter.Advance();
+    }
+    content::NotificationService::current()->Notify(
+        NOTIFICATION_BROWSER_PLUGIN_GUEST_CRASHED,
+        content::Source<BrowserPluginHost>(this),
+        content::NotificationService::NoDetails());
+  }
+}
+
+void BrowserPluginHost::Observe(
+    int type,
+    const NotificationSource& source,
+    const NotificationDetails& details) {
+  switch (type) {
+    case NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED: {
+      RenderViewHost* render_view_host =
+          Details<RenderViewHost>(details).ptr();
+      // BrowserPluginHostHelper is destroyed when its associated RenderViewHost
+      // is destroyed.
+      new BrowserPluginHostHelper(this, render_view_host);
+      break;
+    }
+    case NOTIFICATION_WEB_CONTENTS_VISIBILITY_CHANGED: {
+      bool visible = *Details<bool>(details).ptr();
+      // If the embedder is hidden we need to hide the guests as well.
+      for (GuestMap::const_iterator it = guests_.begin();
+          it != guests_.end(); ++it) {
+        WebContents* web_contents = it->first;
+        if (visible)
+          web_contents->WasShown();
+        else
+          web_contents->WasHidden();
+      }
+      break;
+    }
+    default:
+      NOTREACHED() << "Unexpected notification type: " << type;
+  }
+}
+
+}  // namespace content