Keep event page alive when there's some Pepper plugin on it.

extensions/browser/extension_web_contents_observer.cc

 // Copyright 2014 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 "extensions/browser/extension_web_contents_observer.h"
 
 #include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/site_instance.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extensions_browser_client.h"
 #include "extensions/browser/mojo/service_registration.h"
 #include "extensions/browser/process_manager.h"
 #include "extensions/browser/view_type_utils.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension_messages.h"
+#include "extensions/common/view_type.h"
 
 namespace extensions {
 namespace {
 
 const Extension* GetExtensionForRenderFrame(
     content::RenderFrameHost* render_frame_host) {
   content::SiteInstance* site_instance = render_frame_host->GetSiteInstance();
   GURL url = render_frame_host->GetLastCommittedURL();
   if (!url.is_empty()) {
     if (site_instance->GetSiteURL().GetOrigin() != url.GetOrigin())
@@ skipping 117 matching lines @@
 }
 
 void ExtensionWebContentsObserver::NotifyRenderViewType(
     content::RenderViewHost* render_view_host) {
   if (render_view_host) {
     render_view_host->Send(new ExtensionMsg_NotifyRenderViewType(
         render_view_host->GetRoutingID(), GetViewType(web_contents())));
   }
 }
 
+void ExtensionWebContentsObserver::PepperInstanceCreated() {
+  if (GetViewType(web_contents()) == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {

[not at google - send to devlin, 2015/05/11 17:53:48]

I'm not sure I'd bother with this extra "is background page" check, just adds a
little bit of complexity.

[bartfab (slow), 2015/05/18 09:57:41]

If we leave out this check, we will be keeping background pages alive even if
there is a NaCl module in the main/foreground page. That seems wasteful?

[emaxx, 2015/05/18 15:06:30]

I've already talked to Ben about that. The point is that when there're some
main/foreground pages, the keepalive count is non-zero anyway, so in fact we
won't change anything.

[emaxx, 2015/05/18 15:06:30]

OK, removed this check as it didn't make much difference.

+    ProcessManager* process_manager = ProcessManager::Get(browser_context_);

[bartfab (slow), 2015/05/18 09:57:41]

Nit 1: const pointer.
Nit 2: If you move this inside the conditional that follows, we will avoid
needlessly getting a |process_manager| in the case that |extension| turns out to
be a nullptr.

[emaxx, 2015/05/18 15:06:30]

1: Done.
2: Didn't get your point: the ProcessManager is required in the next line
already.

[bartfab (slow), 2015/05/19 10:34:58]

Nevermind :).

+    const Extension* extension =

[bartfab (slow), 2015/05/18 09:57:41]

Nit 1: const pointer.
Nit 2: #include "extensions/common/extension.h"

[emaxx, 2015/05/18 15:06:30]

Done.

+        process_manager->GetExtensionForWebContents(web_contents());
+    if (extension)
+      process_manager->IncrementLazyKeepaliveCount(extension);
+  }
+}
+
+void ExtensionWebContentsObserver::PepperInstanceDeleted() {
+  if (GetViewType(web_contents()) == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
+    ProcessManager* process_manager = ProcessManager::Get(browser_context_);

[bartfab (slow), 2015/05/18 09:57:41]

Nit 1: const pointer.
Nit 2: As above, better move this inside the conditional.

+    const Extension* extension =

[bartfab (slow), 2015/05/18 09:57:41]

Nit: const pointer.

+        process_manager->GetExtensionForWebContents(web_contents());
+    if (extension)
+      process_manager->DecrementLazyKeepaliveCount(extension);
+  }
+}
+
 const Extension* ExtensionWebContentsObserver::GetExtension(
     content::RenderViewHost* render_view_host) {
   std::string extension_id = GetExtensionId(render_view_host);
   if (extension_id.empty())
     return NULL;
 
   // May be null if the extension doesn't exist, for example if somebody typos
   // a chrome-extension:// URL.
   return ExtensionRegistry::Get(browser_context_)
       ->GetExtensionById(extension_id, ExtensionRegistry::ENABLED);
 }
 
 // static
 std::string ExtensionWebContentsObserver::GetExtensionId(
     content::RenderViewHost* render_view_host) {
   // Note that due to ChromeContentBrowserClient::GetEffectiveURL(), hosted apps
   // (excluding bookmark apps) will have a chrome-extension:// URL for their
   // site, so we can ignore that wrinkle here.
   const GURL& site = render_view_host->GetSiteInstance()->GetSiteURL();
 
   if (!site.SchemeIs(kExtensionScheme))
     return std::string();
 
   return site.host();
 }
 
 }  // namespace extensions