Bug 1350640 - Send blocklist state on plugin list update; r=bsmedberg

Instead of synchronously checking the blocklist, package each plugin's
blocklist state with it when sending the information to the content
process. Whenever the blocklist is changed, just resend the whole
plugin list.

MozReview-Commit-ID: 1AX1EDdTRqb

dom/plugins/base/nsPluginHost.cpp

@@ -2365,6 +2365,7 @@ nsPluginHost::SetPluginsInContent(uint32_t aPluginEpoch,
       // Don't add the same plugin again.
       if (nsPluginTag* existing = PluginWithId(tag.id())) {
         UpdateInMemoryPluginInfo(existing);
+        existing->SetBlocklistState(tag.blocklistState());
         continue;
       }
 
@@ -2382,7 +2383,8 @@ nsPluginHost::SetPluginsInContent(uint32_t aPluginEpoch,
                                                tag.supportsAsyncRender(),
                                                tag.lastModifiedTime(),
                                                tag.isFromExtension(),
-                                               tag.sandboxLevel());
+                                               tag.sandboxLevel(),
+                                               tag.blocklistState());
       AddPluginTag(pluginTag);
     }
 
@@ -2611,6 +2613,11 @@ nsPluginHost::SendPluginsToContent()
     /// to be more sane and avoid this dance
     nsPluginTag *tag = static_cast<nsPluginTag *>(basetag.get());
 
+    uint32_t blocklistState;
+    if (NS_WARN_IF(NS_FAILED(tag->GetBlocklistState(&blocklistState)))) {
+      return NS_ERROR_FAILURE;
+    }
+
     pluginTags.AppendElement(PluginTag(tag->mId,
                                        tag->Name(),
                                        tag->Description(),
@@ -2624,7 +2631,8 @@ nsPluginHost::SendPluginsToContent()
                                        tag->Version(),
                                        tag->mLastModifiedTime,
                                        tag->IsFromExtension(),
-                                       tag->mSandboxLevel));
+                                       tag->mSandboxLevel,
+                                       blocklistState));
   }
   nsTArray<dom::ContentParent*> parents;
   dom::ContentParent::GetAll(parents);
@@ -3489,6 +3497,13 @@ NS_IMETHODIMP nsPluginHost::Observe(nsISupports *aSubject,
       plugin->InvalidateBlocklistState();
       plugin = plugin->mNext;
     }
+    // We update blocklists asynchronously by just sending a new plugin list to
+    // content.
+    if (XRE_IsParentProcess()) {
+      // We'll need to repack our tags and send them to content again.
+      IncrementChromeEpoch();
+      SendPluginsToContent();
+    }
   }
 #ifdef MOZ_WIDGET_ANDROID
   if (!strcmp("application-background", aTopic)) {