Add support for render-ahead

For periods of time during which latency is less important
allow a client to request a deeper render-ahead pipeline.

The latency tradeoff results in less overall visual jank

Test: none, only used by macrobench

Change-Id: I516203b70bdc75b6415fa08bf9c4fb1b598b0102
diff --git a/libs/hwui/Properties.cpp b/libs/hwui/Properties.cpp
index 0a6c45b..7b14322 100644
--- a/libs/hwui/Properties.cpp
+++ b/libs/hwui/Properties.cpp
@@ -36,6 +36,7 @@
 bool Properties::skipEmptyFrames = true;
 bool Properties::useBufferAge = true;
 bool Properties::enablePartialUpdates = true;
+bool Properties::usePresentTime = true;
 
 DebugLevel Properties::debugLevel = kDebugDisabled;
 OverdrawColorSet Properties::overdrawColorSet = OverdrawColorSet::Default;
@@ -135,6 +136,7 @@
     skipEmptyFrames = property_get_bool(PROPERTY_SKIP_EMPTY_DAMAGE, true);
     useBufferAge = property_get_bool(PROPERTY_USE_BUFFER_AGE, true);
     enablePartialUpdates = property_get_bool(PROPERTY_ENABLE_PARTIAL_UPDATES, true);
+    usePresentTime = property_get_bool(PROPERTY_USE_PRESENT_TIME, true);
 
     filterOutTestOverhead = property_get_bool(PROPERTY_FILTER_TEST_OVERHEAD, false);