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

extensions/browser/extension_web_contents_observer.cc

Index: extensions/browser/extension_web_contents_observer.cc
diff --git a/extensions/browser/extension_web_contents_observer.cc b/extensions/browser/extension_web_contents_observer.cc
index 5ba2ebb5fcf81f9d3306e921877d52012bb3d44c..5f6861423787a1c7a284b36713ae13ca731c8233 100644
--- a/extensions/browser/extension_web_contents_observer.cc
+++ b/extensions/browser/extension_web_contents_observer.cc
@@ -19,6 +19,7 @@
 #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 {
@@ -156,6 +157,26 @@ void ExtensionWebContentsObserver::NotifyRenderViewType(
   }
 }
 
+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);