Revert "Avoid a potential race condition on mDisplays"

This reverts commit 8d6c16dc3dc8b88a0046f53668a4e3be074507ff.

Bug: b/37282502
Change-Id: Ibf64607f9e14ede201510e2c1b502c49a31e9f2a
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 219d662..46121cf 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -184,9 +184,8 @@
     void repaintEverything();
 
     // returns the default Display
-    sp<const DisplayDevice> getDefaultDisplayDevice() {
-        Mutex::Autolock _l(mStateLock);
-        return getDefaultDisplayDeviceLocked();
+    sp<const DisplayDevice> getDefaultDisplayDevice() const {
+        return getDisplayDevice(mBuiltinDisplays[DisplayDevice::DISPLAY_PRIMARY]);
     }
 
     // utility function to delete a texture on the main thread
@@ -305,7 +304,7 @@
      * HWComposer::EventHandler interface
      */
     virtual void onVSyncReceived(HWComposer* composer, int type, nsecs_t timestamp);
-    virtual void onHotplugReceived(HWComposer* composer, int disp, bool connected);
+    virtual void onHotplugReceived(int disp, bool connected);
     virtual void onInvalidateReceived(HWComposer* composer);
 
     /* ------------------------------------------------------------------------
@@ -440,12 +439,6 @@
         return mDisplays.valueFor(dpy);
     }
 
-    sp<const DisplayDevice> getDefaultDisplayDeviceLocked() const {
-        return getDisplayDevice(mBuiltinDisplays[DisplayDevice::DISPLAY_PRIMARY]);
-    }
-
-    void createDefaultDisplayDevice();
-
     int32_t getDisplayType(const sp<IBinder>& display) {
         if (!display.get()) return NAME_NOT_FOUND;
         for (int i = 0; i < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES; ++i) {