Bug 1859625 Part 1: Stop sending the GetGfxVars message. r=ipc-reviewers,mccr8

Differential Revision: https://phabricator.services.mozilla.com/D192996

dom/ipc/ContentParent.cpp

@@ -3380,19 +3380,6 @@ int32_t ContentParent::Pid() const {
   return ReleaseAssertedCast<int32_t>(pid);
 }
 
-mozilla::ipc::IPCResult ContentParent::RecvGetGfxVars(
-    nsTArray<GfxVarUpdate>* aVars) {
-  // Ensure gfxVars is initialized (for xpcshell tests).
-  gfxVars::Initialize();
-
-  *aVars = gfxVars::FetchNonDefaultVars();
-
-  // Now that content has initialized gfxVars, we can start listening for
-  // updates.
-  gfxVars::AddReceiver(this);
-  return IPC_OK();
-}
-
 void ContentParent::OnCompositorUnexpectedShutdown() {
   GPUProcessManager* gpm = GPUProcessManager::Get();
 

dom/ipc/ContentParent.h

@@ -972,8 +972,6 @@ class ContentParent final : public PContentParent,
   bool DeallocPWebBrowserPersistDocumentParent(
       PWebBrowserPersistDocumentParent* aActor);
 
-  mozilla::ipc::IPCResult RecvGetGfxVars(nsTArray<GfxVarUpdate>* aVars);
-
   mozilla::ipc::IPCResult RecvSetClipboard(const IPCTransferable& aTransferable,
                                            const int32_t& aWhichClipboard);
 

dom/ipc/PContent.ipdl

@@ -1139,9 +1139,6 @@ parent:
                           bool hasValidUserGestureActivation);
     async ExtProtocolChannelConnectParent(uint64_t registrarId);
 
-    // PrefService message
-    sync GetGfxVars() returns (GfxVarUpdate[] vars);
-
     sync SyncMessage(nsString aMessage, ClonedMessageData aData)
       returns (StructuredCloneData[] retval);
 

gfx/config/gfxVars.cpp

@@ -47,17 +47,12 @@ void gfxVars::Initialize() {
   sVarList = new nsTArray<gfxVars::VarBase*>();
   sInstance = new gfxVars;
 
-  // Note the GPU process is not handled here - it cannot send sync
-  // messages, so instead the initial data is pushed down.
-  if (XRE_IsContentProcess()) {
-    MOZ_ASSERT(gGfxVarInitUpdates,
-               "Initial updates should be provided in content process");
-    if (!gGfxVarInitUpdates) {
-      // No provided initial updates, sync-request them from parent.
-      nsTArray<GfxVarUpdate> initUpdates;
-      dom::ContentChild::GetSingleton()->SendGetGfxVars(&initUpdates);
-      gGfxVarInitUpdates = new nsTArray<GfxVarUpdate>(std::move(initUpdates));
-    }
+  // Content processes should have gotten a call to SetValuesForInitialize,
+  // which will have set gGfxVarInitUpdates.
+  MOZ_ASSERT_IF(XRE_IsContentProcess(), gGfxVarInitUpdates);
+
+  if (gGfxVarInitUpdates) {
+    // Apply any updates from gGfxVarInitUpdates.
     for (const auto& varUpdate : *gGfxVarInitUpdates) {
       ApplyUpdate(varUpdate);
     }

ipc/ipdl/sync-messages.ini

@@ -56,8 +56,6 @@ description = JS MessageManager implementation
 description = legacy sync IPC - please add detailed description
 [PContent::PURLClassifier]
 description = legacy sync IPC - please add detailed description
-[PContent::GetGfxVars]
-description = legacy sync IPC - please add detailed description
 [PContent::GetClipboard]
 description = Legacy synchronous clipboard API
 [PContent::ClipboardHasType]