Add support for external out-of-process PPAPI plugins in the browser.

- Modifies content::BrowserPpapiHostImpl so it's not ref-counted.
- Adds a public content API method, BrowserPpapiHost::CreateExternalPluginProcess
  which allows the embedder to associate a browser ppapi host with a plugin process.
- Adds a public content API method, ContentBrowserClient::GetExternalBrowserPpapiHost,
  so content can track instance creation and deletion for external plugins (e.g. NaCl)
- Removes the content API method EnablePepperSupportForChannel. This is now done
  when creating the BrowserPpapiHost.
BUG=116317
TEST=none

Review URL: https://chromiumcodereview.appspot.com/11368019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@166480 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 79 insertions, 29 deletions

diff --git a/content/browser/renderer_host/pepper/browser_ppapi_host_impl.cc b/content/browser/renderer_host/pepper/browser_ppapi_host_impl.cc
index dedd51e..2cb3522 100644
--- a/content/browser/renderer_host/pepper/browser_ppapi_host_impl.cc
+++ b/content/browser/renderer_host/pepper/browser_ppapi_host_impl.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/pepper/browser_ppapi_host_impl.h"
+#include "content/browser/renderer_host/pepper/pepper_message_filter.h"
 
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_view_host.h"
@@ -10,28 +11,41 @@
 
 namespace content {
 
+// static
+BrowserPpapiHost* BrowserPpapiHost::CreateExternalPluginProcess(
+    IPC::Sender* sender,
+    ppapi::PpapiPermissions permissions,
+    base::ProcessHandle plugin_child_process,
+    IPC::ChannelProxy* channel,
+    net::HostResolver* host_resolver,
+    int render_process_id,
+    int render_view_id) {
+  BrowserPpapiHostImpl* browser_ppapi_host =
+      new BrowserPpapiHostImpl(sender, permissions);
+  browser_ppapi_host->set_plugin_process_handle(plugin_child_process);
+
+  channel->AddFilter(
+      new PepperMessageFilter(PepperMessageFilter::NACL,
+                              host_resolver,
+                              render_process_id,
+                              render_view_id));
+
+  return browser_ppapi_host;
+}
+
 BrowserPpapiHostImpl::BrowserPpapiHostImpl(
     IPC::Sender* sender,
     const ppapi::PpapiPermissions& permissions)
     : ppapi_host_(sender, permissions),
       plugin_process_handle_(base::kNullProcessHandle) {
+  message_filter_ = new HostMessageFilter(&ppapi_host_);
   ppapi_host_.AddHostFactoryFilter(scoped_ptr<ppapi::host::HostFactory>(
       new ContentBrowserPepperHostFactory(this)));
 }
 
 BrowserPpapiHostImpl::~BrowserPpapiHostImpl() {
-}
-
-bool BrowserPpapiHostImpl::OnMessageReceived(const IPC::Message& msg) {
-  /* TODO(brettw) when we add messages, here, the code should look like this:
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(BrowserPpapiHostImpl, msg)
-    // Add necessary message handlers here.
-    IPC_MESSAGE_UNHANDLED(handled = ppapi_host_.OnMessageReceived(msg))
-  IPC_END_MESSAGE_MAP();
-  return handled;
-  */
-  return ppapi_host_.OnMessageReceived(msg);
+  // Notify the filter so it won't foward messages to us.
+  message_filter_->OnHostDestroyed();
 }
 
 ppapi::host::PpapiHost* BrowserPpapiHostImpl::GetPpapiHost() {
@@ -84,4 +98,26 @@ void BrowserPpapiHostImpl::DeleteInstanceForView(PP_Instance instance) {
   instance_to_view_.erase(found);
 }
 
+bool BrowserPpapiHostImpl::HostMessageFilter::OnMessageReceived(
+    const IPC::Message& msg) {
+  // Don't forward messages if our owner object has been destroyed.
+  if (!ppapi_host_)
+    return false;
+
+  /* TODO(brettw) when we add messages, here, the code should look like this:
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(BrowserPpapiHostImpl, msg)
+    // Add necessary message handlers here.
+    IPC_MESSAGE_UNHANDLED(handled = ppapi_host_->OnMessageReceived(msg))
+  IPC_END_MESSAGE_MAP();
+  return handled;
+  */
+  return ppapi_host_->OnMessageReceived(msg);
+}
+
+void BrowserPpapiHostImpl::HostMessageFilter::OnHostDestroyed() {
+  DCHECK(ppapi_host_);
+  ppapi_host_ = NULL;
+}
+
 }  // namespace content
diff --git a/content/browser/renderer_host/pepper/browser_ppapi_host_impl.h b/content/browser/renderer_host/pepper/browser_ppapi_host_impl.h
index d743d15..bee35a6 100644
--- a/content/browser/renderer_host/pepper/browser_ppapi_host_impl.h
+++ b/content/browser/renderer_host/pepper/browser_ppapi_host_impl.h
@@ -15,24 +15,16 @@
 #include "ipc/ipc_channel_proxy.h"
 #include "ppapi/host/ppapi_host.h"
 
-namespace IPC {
-class Sender;
-}
-
 namespace content {
 
-class CONTENT_EXPORT BrowserPpapiHostImpl
-    : public BrowserPpapiHost,
-      public IPC::ChannelProxy::MessageFilter {
+class CONTENT_EXPORT BrowserPpapiHostImpl : public BrowserPpapiHost {
  public:
   // The creator is responsible for calling set_plugin_process_handle as soon
   // as it is known (we start the process asynchronously so it won't be known
   // when this object is created).
   BrowserPpapiHostImpl(IPC::Sender* sender,
                        const ppapi::PpapiPermissions& permissions);
-
-  // IPC::ChannelProxy::MessageFilter.
-  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
+  virtual ~BrowserPpapiHostImpl();
 
   // BrowserPpapiHost.
   virtual ppapi::host::PpapiHost* GetPpapiHost() OVERRIDE;
@@ -54,6 +46,10 @@ class CONTENT_EXPORT BrowserPpapiHostImpl
                           int render_view_id);
   void DeleteInstanceForView(PP_Instance instance);
 
+  scoped_refptr<IPC::ChannelProxy::MessageFilter> message_filter() {
+    return message_filter_;
+  }
+
  private:
   friend class BrowserPpapiHostTest;
 
@@ -63,7 +59,23 @@ class CONTENT_EXPORT BrowserPpapiHostImpl
   };
   typedef std::map<PP_Instance, RenderViewIDs> InstanceToViewMap;
 
-  virtual ~BrowserPpapiHostImpl();
+  // Implementing MessageFilter on BrowserPpapiHostImpl makes it ref-counted,
+  // preventing us from returning these to embedders without holding a
+  // reference. To avoid that, define a message filter object.
+  class HostMessageFilter : public IPC::ChannelProxy::MessageFilter {
+   public:
+    explicit HostMessageFilter(ppapi::host::PpapiHost* ppapi_host)
+        : ppapi_host_(ppapi_host) {}
+    // IPC::ChannelProxy::MessageFilter.
+    virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
+
+    void OnHostDestroyed();
+
+   private:
+    virtual ~HostMessageFilter() {}
+
+    ppapi::host::PpapiHost* ppapi_host_;
+  };
 
   ppapi::host::PpapiHost ppapi_host_;
   base::ProcessHandle plugin_process_handle_;
@@ -72,6 +84,8 @@ class CONTENT_EXPORT BrowserPpapiHostImpl
   // RenderProcess/RenderView IDs.
   InstanceToViewMap instance_to_view_;
 
+  scoped_refptr<HostMessageFilter> message_filter_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserPpapiHostImpl);
 };
 
diff --git a/content/browser/renderer_host/pepper/browser_ppapi_host_test.cc b/content/browser/renderer_host/pepper/browser_ppapi_host_test.cc
index 42fc6c0..941782c 100644
--- a/content/browser/renderer_host/pepper/browser_ppapi_host_test.cc
+++ b/content/browser/renderer_host/pepper/browser_ppapi_host_test.cc
@@ -10,10 +10,10 @@
 namespace content {
 
 BrowserPpapiHostTest::BrowserPpapiHostTest()
-    : sink_(),
-      ppapi_host_(new BrowserPpapiHostImpl(
-            &sink_,
-            ppapi::PpapiPermissions::AllPermissions())) {
+    : sink_() {
+  ppapi_host_.reset(new BrowserPpapiHostImpl(
+                        &sink_,
+                        ppapi::PpapiPermissions::AllPermissions()));
   ppapi_host_->set_plugin_process_handle(base::GetCurrentProcessHandle());
 }
 
@@ -21,7 +21,7 @@ BrowserPpapiHostTest::~BrowserPpapiHostTest() {
 }
 
 BrowserPpapiHost* BrowserPpapiHostTest::GetBrowserPpapiHost() {
-  return ppapi_host_;
+  return ppapi_host_.get();
 }
 
 }  // namespace content
diff --git a/content/browser/renderer_host/pepper/browser_ppapi_host_test.h b/content/browser/renderer_host/pepper/browser_ppapi_host_test.h
index d9e73a1..3f375ee 100644
--- a/content/browser/renderer_host/pepper/browser_ppapi_host_test.h
+++ b/content/browser/renderer_host/pepper/browser_ppapi_host_test.h
@@ -27,7 +27,7 @@ class BrowserPpapiHostTest {
  private:
   ppapi::proxy::ResourceMessageTestSink sink_;
 
-  scoped_refptr<BrowserPpapiHostImpl> ppapi_host_;
+  scoped_ptr<BrowserPpapiHostImpl> ppapi_host_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserPpapiHostTest);
 };