SF: BufferingStats state to SFBE

Move BufferingStats state to SurfaceFlingerBE

Test: build
Change-Id: I4404607e44b078bb70dca9562c8d3b180702fe15
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index ce336bf..27a0559 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3695,8 +3695,8 @@
 
 void SurfaceFlinger::recordBufferingStats(const char* layerName,
         std::vector<OccupancyTracker::Segment>&& history) {
-    Mutex::Autolock lock(mBufferingStatsMutex);
-    auto& stats = mBufferingStats[layerName];
+    Mutex::Autolock lock(getBE().mBufferingStatsMutex);
+    auto& stats = getBE().mBufferingStats[layerName];
     for (const auto& segment : history) {
         if (!segment.usedThirdBuffer) {
             stats.twoBufferTime += segment.totalTime;
@@ -3725,12 +3725,12 @@
     result.append("Buffering stats:\n");
     result.append("  [Layer name] <Active time> <Two buffer> "
             "<Double buffered> <Triple buffered>\n");
-    Mutex::Autolock lock(mBufferingStatsMutex);
+    Mutex::Autolock lock(getBE().mBufferingStatsMutex);
     typedef std::tuple<std::string, float, float, float> BufferTuple;
     std::map<float, BufferTuple, std::greater<float>> sorted;
-    for (const auto& statsPair : mBufferingStats) {
+    for (const auto& statsPair : getBE().mBufferingStats) {
         const char* name = statsPair.first.c_str();
-        const BufferingStats& stats = statsPair.second;
+        const SurfaceFlingerBE::BufferingStats& stats = statsPair.second;
         if (stats.numSegments == 0) {
             continue;
         }