skpbench: add option for gpu timing

tools/gpu/TestContext.h

Index: tools/gpu/TestContext.h
diff --git a/tools/gpu/TestContext.h b/tools/gpu/TestContext.h
index d01cb02af2ad833e256b61f5e87ba4d348bf4f7d..8722a337b3a92a62731cde805ae9100a8135f262 100644
--- a/tools/gpu/TestContext.h
+++ b/tools/gpu/TestContext.h
@@ -14,6 +14,9 @@
 #include "../private/SkTemplates.h"
 
 namespace sk_gpu_test {
+
+class GpuTimer;
+
 /**
  * An offscreen 3D context. This class is intended for Skia's internal testing needs and not
  * for general use.
@@ -27,6 +30,9 @@ public:
     bool fenceSyncSupport() const { return fFenceSync != nullptr; }
     FenceSync* fenceSync() { SkASSERT(fFenceSync); return fFenceSync; }
 
+    bool gpuTimingSupport() const { return fGpuTimer != nullptr; }
+    GpuTimer* gpuTimer() const { SkASSERT(fGpuTimer); return fGpuTimer; }
+
     bool getMaxGpuFrameLag(int *maxFrameLag) const {
         if (!fFenceSync) {
             return false;
@@ -75,7 +81,8 @@ public:
     virtual void finish() = 0;
 
 protected:
-    FenceSync* fFenceSync;
+    SkAutoTDelete<FenceSync>   fFenceSync;
+    SkAutoTDelete<GpuTimer>    fGpuTimer;
 
     TestContext();