Keep NaCl plugins used in app background pages alive when active.

Activity in Native Client plugins results in IPC messages
sent to the BrowserPpapiHostImpl and routed to call
extensions::ProcessManager::KeepaliveImpulse.

Implementation patch, to be followed by tests. See:
https://codereview.chromium.org/111563006/ Tests.
https://codereview.chromium.org/105873003/ Cumulative patch.

Design doc: 
https://docs.google.com/a/chromium.org/document/d/1mI0lS1rfAf-BAGLmWAEcWy37Xq9dOvgfMx8OqeUMXts/edit#

BUG=298339

Review URL: https://codereview.chromium.org/61063003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241702 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 84 insertions, 9 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 c3c2c6f3..fd2c82e 100644
--- a/content/browser/renderer_host/pepper/browser_ppapi_host_impl.cc
+++ b/content/browser/renderer_host/pepper/browser_ppapi_host_impl.cc
@@ -7,9 +7,9 @@
 #include "content/browser/renderer_host/pepper/pepper_message_filter.h"
 #include "content/browser/tracing/trace_message_filter.h"
 #include "content/common/pepper_renderer_instance_data.h"
-#include "content/public/browser/render_view_host.h"
 #include "content/public/common/process_type.h"
 #include "ipc/ipc_message_macros.h"
+#include "ppapi/proxy/ppapi_messages.h"
 
 namespace content {
 
@@ -55,7 +55,7 @@ BrowserPpapiHostImpl::BrowserPpapiHostImpl(
       in_process_(in_process),
       external_plugin_(external_plugin),
       ssl_context_helper_(new SSLContextHelper()) {
-  message_filter_ = new HostMessageFilter(ppapi_host_.get());
+  message_filter_ = new HostMessageFilter(ppapi_host_.get(), this);
   ppapi_host_->AddHostFactoryFilter(scoped_ptr<ppapi::host::HostFactory>(
       new ContentBrowserPepperHostFactory(this)));
 }
@@ -126,6 +126,11 @@ GURL BrowserPpapiHostImpl::GetPluginURLForInstance(PP_Instance instance) {
   return found->second.plugin_url;
 }
 
+void BrowserPpapiHostImpl::SetOnKeepaliveCallback(
+      const BrowserPpapiHost::OnKeepaliveCallback& callback) {
+  on_keepalive_callback_ = callback;
+}
+
 void BrowserPpapiHostImpl::AddInstance(
     PP_Instance instance,
     const PepperRendererInstanceData& instance_data) {
@@ -142,26 +147,67 @@ void BrowserPpapiHostImpl::DeleteInstance(PP_Instance instance) {
   instance_map_.erase(found);
 }
 
+BrowserPpapiHostImpl::HostMessageFilter::HostMessageFilter(
+    ppapi::host::PpapiHost* ppapi_host,
+    BrowserPpapiHostImpl* browser_ppapi_host_impl)
+        : ppapi_host_(ppapi_host),
+          browser_ppapi_host_impl_(browser_ppapi_host_impl) {
+}
+
 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)
+  IPC_BEGIN_MESSAGE_MAP(BrowserPpapiHostImpl::HostMessageFilter, msg)
     // Add necessary message handlers here.
+    IPC_MESSAGE_HANDLER(PpapiHostMsg_Keepalive, OnKeepalive)
     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;
+  browser_ppapi_host_impl_ = NULL;
+}
+
+BrowserPpapiHostImpl::HostMessageFilter::~HostMessageFilter() {
+}
+
+void BrowserPpapiHostImpl::HostMessageFilter::OnKeepalive() {
+  if (browser_ppapi_host_impl_)
+    browser_ppapi_host_impl_->OnKeepalive();
+}
+
+void BrowserPpapiHostImpl::OnKeepalive() {
+  // An instance has been active. The on_keepalive_callback_ will be
+  // used to permit the content embedder to handle this, e.g. by tracking
+  // activity and shutting down processes that go idle.
+  //
+  // Currently embedders do not need to distinguish between instances having
+  // different idle state, and thus this implementation handles all instances
+  // for this module together.
+
+  if (on_keepalive_callback_.is_null())
+    return;
+
+  BrowserPpapiHost::OnKeepaliveInstanceData
+      instance_data(instance_map_.size());
+
+  InstanceMap::iterator instance = instance_map_.begin();
+  int i = 0;
+  while (instance != instance_map_.end()) {
+    instance_data[i].render_process_id = instance->second.render_process_id;
+    instance_data[i].render_view_id = instance->second.render_view_id;
+    instance_data[i].document_url = instance->second.document_url;
+    ++instance;
+    ++i;
+  }
+  on_keepalive_callback_.Run(instance_data, profile_data_directory_);
 }
 
 }  // 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 5d95342..d987bd4 100644
--- a/content/browser/renderer_host/pepper/browser_ppapi_host_impl.h
+++ b/content/browser/renderer_host/pepper/browser_ppapi_host_impl.h
@@ -12,6 +12,7 @@
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "content/browser/renderer_host/pepper/content_browser_pepper_host_factory.h"
 #include "content/browser/renderer_host/pepper/ssl_context_helper.h"
 #include "content/common/content_export.h"
@@ -52,6 +53,9 @@ class CONTENT_EXPORT BrowserPpapiHostImpl : public BrowserPpapiHost {
   virtual const base::FilePath& GetProfileDataDirectory() OVERRIDE;
   virtual GURL GetDocumentURLForInstance(PP_Instance instance) OVERRIDE;
   virtual GURL GetPluginURLForInstance(PP_Instance instance) OVERRIDE;
+  virtual void SetOnKeepaliveCallback(
+      const BrowserPpapiHost::OnKeepaliveCallback& callback) OVERRIDE;
+
 
   void set_plugin_process_handle(base::ProcessHandle handle) {
     plugin_process_handle_ = handle;
@@ -83,19 +87,27 @@ class CONTENT_EXPORT BrowserPpapiHostImpl : public BrowserPpapiHost {
   // 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) {}
+    HostMessageFilter(ppapi::host::PpapiHost* ppapi_host,
+                      BrowserPpapiHostImpl* browser_ppapi_host_impl);
+
     // IPC::ChannelProxy::MessageFilter.
     virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
 
     void OnHostDestroyed();
 
    private:
-    virtual ~HostMessageFilter() {}
+    virtual ~HostMessageFilter();
+
+    void OnKeepalive();
 
+    // Non owning pointers cleared in OnHostDestroyed()
     ppapi::host::PpapiHost* ppapi_host_;
+    BrowserPpapiHostImpl* browser_ppapi_host_impl_;
   };
 
+  // Reports plugin activity to the callback set with SetOnKeepaliveCallback.
+  void OnKeepalive();
+
   scoped_ptr<ppapi::host::PpapiHost> ppapi_host_;
   base::ProcessHandle plugin_process_handle_;
   std::string plugin_name_;
@@ -118,6 +130,8 @@ class CONTENT_EXPORT BrowserPpapiHostImpl : public BrowserPpapiHost {
 
   scoped_refptr<HostMessageFilter> message_filter_;
 
+  BrowserPpapiHost::OnKeepaliveCallback on_keepalive_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserPpapiHostImpl);
 };
 
diff --git a/content/public/browser/browser_ppapi_host.h b/content/public/browser/browser_ppapi_host.h
index 45f997e..ce76d16 100644
--- a/content/public/browser/browser_ppapi_host.h
+++ b/content/public/browser/browser_ppapi_host.h
@@ -34,6 +34,17 @@ namespace content {
 // lives entirely on the I/O thread.
 class CONTENT_EXPORT BrowserPpapiHost {
  public:
+  struct OnKeepaliveInstanceStruct {
+    int render_process_id;
+    int render_view_id;
+    GURL document_url;
+  };
+  typedef std::vector<OnKeepaliveInstanceStruct> OnKeepaliveInstanceData;
+  typedef base::Callback<
+      void (const OnKeepaliveInstanceData& instance_data,
+            const base::FilePath& profile_data_directory)>
+      OnKeepaliveCallback;
+
   // Creates a browser host and sets up an out-of-process proxy for an external
   // pepper plugin process.
   static BrowserPpapiHost* CreateExternalPluginProcess(
@@ -81,6 +92,10 @@ class CONTENT_EXPORT BrowserPpapiHost {
   // Get the Document/Plugin URLs for the given PP_Instance.
   virtual GURL GetDocumentURLForInstance(PP_Instance instance) = 0;
   virtual GURL GetPluginURLForInstance(PP_Instance instance) = 0;
+
+  // Sets a callback the BrowserPpapiHost will run when the plugin messages
+  // that it is active.
+  virtual void SetOnKeepaliveCallback(const OnKeepaliveCallback& callback) = 0;
 };
 
 }  // namespace content