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

chrome/browser/nacl_host/nacl_browser_delegate_impl.cc

Index: chrome/browser/nacl_host/nacl_browser_delegate_impl.cc
diff --git a/chrome/browser/nacl_host/nacl_browser_delegate_impl.cc b/chrome/browser/nacl_host/nacl_browser_delegate_impl.cc
index a0e92bdc6839b1e3b57e5ab74587166f2b38154d..29fc0e1ccc3a07c04b9caaceea47737d6cf6d5d0 100644
--- a/chrome/browser/nacl_host/nacl_browser_delegate_impl.cc
+++ b/chrome/browser/nacl_host/nacl_browser_delegate_impl.cc
@@ -9,15 +9,20 @@
 #include "base/strings/string_util.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/component_updater/pnacl/pnacl_component_installer.h"
+#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/nacl_host/nacl_infobar_delegate.h"
+#include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_host/pepper/chrome_browser_pepper_host_factory.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_paths_internal.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/logging_chrome.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/site_instance.h"
 #include "extensions/browser/info_map.h"
+#include "extensions/browser/process_manager.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/manifest_handlers/shared_module_info.h"
@@ -26,6 +31,77 @@
 
 using extensions::SharedModuleInfo;
 
+namespace {
+
+// Handles an extension's NaCl process transitioning in or out of idle state by
+// relaying the state to the extension's process manager.
+//
+// A NaCl instance, when active, sends keepalive IPCs to the browser process
+// BrowserPpapiHost at a trottled rate. The content::BrowserPpapiHost passes

[Mark Seaborn, 2013/12/16 22:40:46]

Typo: "throttled".  Could you emphasise here that the keepalive IPCs only occur
for NaCl processes that are part of extensions, not on normal web pages?

[scheib, 2013/12/16 23:13:44]

Done. "throttled".
Bugged: https://code.google.com/p/chromium/issues/detail?id=329037 for not
sending IPCs from normal web pages. IMHO an IPC every 5 seconds is pretty minor
and can be addressed in follow up work.

[Mark Seaborn, 2013/12/18 09:11:43]

Oh, I think I misread "active" in the comment as applying to any instantiated
NaCl process.  Maybe define it by saying "when active (actively making PPAPI
calls or receiving PPAPI callbacks)"?  Given that, I don't think you need to fix
329037.  LGTM still.

+// context information up to the chrome level NaClProcessHost where we use the
+// instance's context to find the associated extension process manager.
+//
+// There is 1:many relationship for extension:nacl-embeds, but only a

[dmichael (off chromium), 2013/12/16 22:17:54]

nit: "is +a+ 1:many"

[scheib, 2013/12/16 23:13:44]

Done.

+// 1:1 relationship for NaClProcessHost:PP_Instance. The content layer doesn't
+// rely on this knowledge because it routes messages for ppapi non-nacl
+// instances as well, though they won't have callbacks set. Here the 1:1
+// assumption is made and DCHECKed.
+void OnKeepaliveOnUIThread(
+    const content::BrowserPpapiHost::OnKeepaliveInstanceData& intance_data,

[Mark Seaborn, 2013/12/16 22:40:46]

"instance_data"

[scheib, 2013/12/16 23:13:44]

Done.

+    const base::FilePath& profile_data_directory) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
+  // Only one instance will exist for NaCl embeds, even when more than one
+  // embed of the same plugin exists on the same page.
+  DCHECK(intance_data.size() == 1);
+  if (intance_data.size() < 1)
+    return;
+
+  content::RenderViewHost* render_view_host = content::RenderViewHost::FromID(
+      intance_data[0].render_process_id, intance_data[0].render_view_id);
+  if (!render_view_host)
+    return;
+
+  content::SiteInstance* site_instance = render_view_host->GetSiteInstance();
+  if (!site_instance)
+    return;
+
+  extensions::ExtensionSystem* extension_system =
+      extensions::ExtensionSystem::GetForBrowserContext(
+          site_instance->GetBrowserContext());
+  if (!extension_system)
+    return;
+
+  const ExtensionService* extension_service =
+      extension_system->extension_service();
+  if (!extension_service)
+    return;
+
+  const extensions::Extension* extension = extension_service->GetExtensionById(
+      intance_data[0].document_url.host(), false);
+  if (!extension)
+    return;
+
+  extensions::ProcessManager* pm = extension_system->process_manager();
+  if (!pm)
+    return;
+
+  pm->KeepaliveImpulse(extension);
+}
+
+// Calls OnKeepaliveOnUIThread on UI thread.
+void OnKeepalive(
+    const content::BrowserPpapiHost::OnKeepaliveInstanceData& intance_data,

[Mark Seaborn, 2013/12/16 22:40:46]

"instance_data"

[scheib, 2013/12/16 23:13:44]

Done.

+    const base::FilePath& profile_data_directory) {
+  DCHECK(!content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
+                                   base::Bind(&OnKeepaliveOnUIThread,
+                                              intance_data,
+                                              profile_data_directory));
+}
+
+}  // namespace
+
 NaClBrowserDelegateImpl::NaClBrowserDelegateImpl(
     extensions::InfoMap* extension_info_map)
     : extension_info_map_(extension_info_map), inverse_debug_patterns_(false) {}
@@ -181,3 +257,8 @@ bool NaClBrowserDelegateImpl::MapUrlToLocalFilePath(
   *file_path = resource_file_path;
   return true;
 }
+
+content::BrowserPpapiHost::OnKeepaliveCallback
+NaClBrowserDelegateImpl::GetOnKeepaliveCallback() {
+  return base::Bind(&OnKeepalive);
+}