SF: Generalize thread safety guards

Replace the guards with a uniform syntax that can be reused with
annotations other than mStateLock and SF_MAIN_THREAD.

Bug: 182939859
Test: Build
Change-Id: I03e6fe5d465111a5882d2fc1c09fe1dc9660aa07
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index f2636b4..97b0e8d 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -64,6 +64,7 @@
 #include "Scheduler/Scheduler.h"
 #include "Scheduler/VsyncModulator.h"
 #include "SurfaceFlingerFactory.h"
+#include "ThreadContext.h"
 #include "TracedOrdinal.h"
 #include "Tracing/LayerTracing.h"
 #include "Tracing/TransactionTracing.h"
@@ -183,11 +184,6 @@
     std::atomic<nsecs_t> mLastSwapTime = 0;
 };
 
-struct SCOPED_CAPABILITY UnnecessaryLock {
-    explicit UnnecessaryLock(Mutex& mutex) ACQUIRE(mutex) {}
-    ~UnnecessaryLock() RELEASE() {}
-};
-
 class SurfaceFlinger : public BnSurfaceComposer,
                        public PriorityDumper,
                        private IBinder::DeathRecipient,
@@ -740,7 +736,7 @@
     void updateLayerGeometry();
 
     void updateInputFlinger();
-    void persistDisplayBrightness(bool needsComposite) REQUIRES(SF_MAIN_THREAD);
+    void persistDisplayBrightness(bool needsComposite) REQUIRES(kMainThreadContext);
     void buildWindowInfos(std::vector<gui::WindowInfo>& outWindowInfos,
                           std::vector<gui::DisplayInfo>& outDisplayInfos);
     void commitInputWindowCommands() REQUIRES(mStateLock);
@@ -973,7 +969,7 @@
     void setCompositorTimingSnapped(const DisplayStatInfo& stats,
                                     nsecs_t compositeToPresentLatency);
 
-    void postFrame();
+    void postFrame() REQUIRES(kMainThreadContext);
 
     /*
      * Display management
@@ -1088,7 +1084,7 @@
     void clearStatsLocked(const DumpArgs& args, std::string& result);
     void dumpTimeStats(const DumpArgs& args, bool asProto, std::string& result) const;
     void dumpFrameTimeline(const DumpArgs& args, std::string& result) const;
-    void logFrameStats();
+    void logFrameStats() REQUIRES(kMainThreadContext);
 
     void dumpVSync(std::string& result) const REQUIRES(mStateLock);
     void dumpStaticScreenStats(std::string& result) const;
@@ -1431,7 +1427,7 @@
         nsecs_t commitStart;
         nsecs_t compositeStart;
         nsecs_t presentEnd;
-    } mPowerHintSessionData GUARDED_BY(SF_MAIN_THREAD);
+    } mPowerHintSessionData GUARDED_BY(kMainThreadContext);
 
     nsecs_t mAnimationTransactionTimeout = s2ns(5);