Fix full draw power usage increase issue

Full draw will be happened on HWUI under 144Hz device,there are
more draw commands under renderFrameImpl than in the 120Hz fps device,
frame.bufferAge() > (int)mSwapHistory.size() resulting in an increase
in power usage.

So need to increase (int)mSwapHistory.size() to 8.

Bug: 397592669
Test: Manual
1.Use the 144Hz device
2.Grab Settings Systrace of the sliding scene
3.Collect the Systrace, and check the drawing dirty area
is the screen area of the entire device

Change-Id: I477d37828f080e64cded9f285c58b7b27cbe6b03

1 files changed, 1 insertions, 1 deletions

diff --git a/libs/hwui/renderthread/CanvasContext.h b/libs/hwui/renderthread/CanvasContext.h
index cb3753822035..c31d0be74cb6 100644
--- a/libs/hwui/renderthread/CanvasContext.h
+++ b/libs/hwui/renderthread/CanvasContext.h
@@ -312,7 +312,7 @@ private:
     };
 
     // Need at least 4 because we do quad buffer. Add a few more for good measure.
-    RingBuffer<SwapHistory, 7> mSwapHistory;
+    RingBuffer<SwapHistory, 8> mSwapHistory;
     // Frame numbers start at 1, 0 means uninitialized
     uint64_t mFrameNumber = 0;
     int64_t mDamageId = 0;