Browser Plugin: Only install BrowserPluginMessageFilter if render process supports BrowserPlugin.

content/browser/renderer_host/render_process_host_impl.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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 340 matching lines @@
 bool g_run_renderer_in_process_ = false;
 
 // static
 void RenderProcessHost::SetMaxRendererProcessCount(size_t count) {
   g_max_renderer_count_override = count;
 }
 
 RenderProcessHostImpl::RenderProcessHostImpl(
     BrowserContext* browser_context,
     StoragePartitionImpl* storage_partition_impl,
+    bool supports_browser_plugin,
     bool is_guest)
         : fast_shutdown_started_(false),
           deleting_soon_(false),
           pending_views_(0),
           visible_widgets_(0),
           backgrounded_(true),
           ALLOW_THIS_IN_INITIALIZER_LIST(cached_dibs_cleaner_(
                 FROM_HERE, base::TimeDelta::FromSeconds(5),
                 this, &RenderProcessHostImpl::ClearTransportDIBCache)),
           is_initialized_(false),
           id_(ChildProcessHostImpl::GenerateChildProcessUniqueId()),
           browser_context_(browser_context),
           storage_partition_impl_(storage_partition_impl),
           sudden_termination_allowed_(true),
           ignore_input_events_(false),
 #if defined(OS_ANDROID)
           dummy_shutdown_event_(false, false),
 #endif
+          supports_browser_plugin_(supports_browser_plugin),

[Charlie Reis, 2013/03/21 01:09:39]

Can you add a CHECK(!is_guest || supports_browser_plugin)?

[Fady Samuel, 2013/03/21 02:51:13]

No, unfortunately.

is_guest does not imply supports_browser_plugin. The latter means that the
process is capable of hosting BrowserPlugins. The former means it's a guest
process. Guests cannot host other BrowserPlugins, at least for webviews.

           is_guest_(is_guest) {
   widget_helper_ = new RenderWidgetHelper();
 
   ChildProcessSecurityPolicyImpl::GetInstance()->Add(GetID());
 
   CHECK(!g_exited_main_message_loop);
   RegisterHost(GetID(), this);
   g_all_hosts.Get().set_check_on_null_data(true);
   // Initialize |child_process_activity_time_| to a reasonable value.
   mark_child_process_activity_time();
@@ skipping 133 matching lines @@
   is_initialized_ = true;
   return true;
 }
 
 void RenderProcessHostImpl::CreateMessageFilters() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   channel_->AddFilter(new ResourceSchedulerFilter(GetID()));
   MediaInternals* media_internals = MediaInternals::GetInstance();;
   // Add BrowserPluginMessageFilter to ensure it gets the first stab at messages
   // from guests.
-  // TODO(fsamuel): Call out to the ContentBrowserClient to decide whether or
-  // not to install the BrowserPluginMessageFilter.
-  scoped_refptr<BrowserPluginMessageFilter> bp_message_filter(
-      new BrowserPluginMessageFilter(GetID(), IsGuest()));
-  channel_->AddFilter(bp_message_filter);
+  if (supports_browser_plugin_) {
+    scoped_refptr<BrowserPluginMessageFilter> bp_message_filter(
+        new BrowserPluginMessageFilter(GetID(), IsGuest()));
+    channel_->AddFilter(bp_message_filter);
+  }
 
   scoped_refptr<RenderMessageFilter> render_message_filter(
       new RenderMessageFilter(
           GetID(),
 #if defined(ENABLE_PLUGINS)
           PluginServiceImpl::GetInstance(),
 #else
           NULL,
 #endif
           GetBrowserContext(),
@@ skipping 164 matching lines @@
     DCHECK(!backgrounded_);
     SetBackgrounded(true);
   }
 }
 
 int RenderProcessHostImpl::VisibleWidgetCount() const {
   return visible_widgets_;
 }
 
 bool RenderProcessHostImpl::IsGuest() const {
   return is_guest_;

[Charlie Reis, 2013/03/21 01:09:39]

Maybe this should be supports_browser_plugin_ && is_guest_?  Best if we notice
if these ever differ.

[Fady Samuel, 2013/03/21 02:51:13]

No, guests don't support browser plugin.

 }
 
 StoragePartition* RenderProcessHostImpl::GetStoragePartition() const {
   return storage_partition_impl_;
 }
 
 void RenderProcessHostImpl::AppendRendererCommandLine(
     CommandLine* command_line) const {
   // Pass the process type first, so it shows first in process listings.
   command_line->AppendSwitchASCII(switches::kProcessType,
@@ skipping 961 matching lines @@
   TRACE_EVENT0("renderer_host",
                "RenderWidgetHostImpl::OnCompositorSurfaceBuffersSwappedNoHost");
   AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
   ack_params.sync_point = 0;
   RenderWidgetHostImpl::AcknowledgeBufferPresent(route_id,
                                                  gpu_process_host_id,
                                                  ack_params);
 }
 
 }  // namespace content