Lock all of SurfaceFlinger::processDisplayAdded for kMainThreadContext instead of just a portion of it.

Also make processDisplayAdded private and not virtual.

Test: Manual testing

BUG: 241285876

Flag: EXEMPT refactor

Change-Id: I50d9e07e52d753713db11883f9cfbfcf245d2cca
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 1038b9f..5f79179 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3975,9 +3975,6 @@
                                                  displaySurface, producer);
 
     if (mScheduler && !display->isVirtual()) {
-        // TODO(b/241285876): Annotate `processDisplayAdded` instead.
-        ftl::FakeGuard guard(kMainThreadContext);
-
         // For hotplug reconnect, renew the registration since display modes have been reloaded.
         mScheduler->registerDisplay(display->getPhysicalId(), display->holdRefreshRateSelector(),
                                     mActiveDisplayId);
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 158bf57..24de02a 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -350,9 +350,6 @@
     // We're reference counted, never destroy SurfaceFlinger directly
     virtual ~SurfaceFlinger();
 
-    virtual void processDisplayAdded(const wp<IBinder>& displayToken, const DisplayDeviceState&)
-            REQUIRES(mStateLock);
-
     virtual std::shared_ptr<renderengine::ExternalTexture> getExternalTextureFromBufferData(
             BufferData& bufferData, const char* layerName, uint64_t transactionId);
 
@@ -1042,6 +1039,8 @@
             const sp<compositionengine::DisplaySurface>& displaySurface,
             const sp<IGraphicBufferProducer>& producer) REQUIRES(mStateLock);
     void processDisplayChangesLocked() REQUIRES(mStateLock, kMainThreadContext);
+    void processDisplayAdded(const wp<IBinder>& displayToken, const DisplayDeviceState&)
+            REQUIRES(mStateLock, kMainThreadContext);
     void processDisplayRemoved(const wp<IBinder>& displayToken)
             REQUIRES(mStateLock, kMainThreadContext);
     void processDisplayChanged(const wp<IBinder>& displayToken,