Spin off GM::runAsBench() from flags.

This will let us kill flags.

BUG=skia:

Review URL: https://codereview.chromium.org/873753002

bench/nanobench.cpp

@@ -503,7 +503,7 @@ public:
         while (fGMs) {
             SkAutoTDelete<skiagm::GM> gm(fGMs->factory()(NULL));
             fGMs = fGMs->next();
-            if (gm->getFlags() & skiagm::GM::kAsBench_Flag) {
+            if (gm->runAsBench()) {
                 fSourceType = "gm";
                 fBenchType  = "micro";
                 return SkNEW_ARGS(GMBench, (gm.detach()));

gm/circularclips.cpp

@@ -26,9 +26,11 @@ public:
 
 protected:
     uint32_t onGetFlags() const SK_OVERRIDE {
-        return kSkipTiled_Flag | kAsBench_Flag;
+        return kSkipTiled_Flag;
     }
 
+    bool runAsBench() const SK_OVERRIDE { return true; }
+
     SkString onShortName() SK_OVERRIDE {
         return SkString("circular-clips");
     }

gm/convexpolyclip.cpp

@@ -215,9 +215,11 @@ protected:
     }
 
     virtual uint32_t onGetFlags() const {
-        return kAsBench_Flag | kSkipTiled_Flag;
+        return kSkipTiled_Flag;
     }
 
+    bool runAsBench() const SK_OVERRIDE { return true; }
+
 private:
     class Clip {
     public:

gm/dashing.cpp

@@ -414,9 +414,11 @@ public:
     Dashing5GM(bool doAA) : fDoAA(doAA) {}
 
 protected:
-    uint32_t onGetFlags() const SK_OVERRIDE { return kAsBench_Flag | kSkipTiled_Flag; }
+    uint32_t onGetFlags() const SK_OVERRIDE { return kSkipTiled_Flag; }
 
-    SkString onShortName() SK_OVERRIDE { 
+    bool runAsBench() const SK_OVERRIDE { return true; }
+
+    SkString onShortName() SK_OVERRIDE {
         if (fDoAA) {
             return SkString("dashing5_aa");
         } else {

gm/gm.h

@@ -53,8 +53,6 @@ namespace skiagm {
 
             kGPUOnly_Flag               = 1 << 9,
 
-            kAsBench_Flag               = 1 << 10, // Run the GM as a benchmark in the bench tool
-
             kNoBBH_Flag                 = 1 << 11, // May draw wrong using a bounding-box hierarchy
         };
 
@@ -74,6 +72,8 @@ namespace skiagm {
         SkISize getISize() { return this->onISize(); }
         const char* getName();
 
+        virtual bool runAsBench() const { return false; }
+
         uint32_t getFlags() const {
             return this->onGetFlags();
         }

gm/multipicturedraw.cpp

@@ -534,7 +534,8 @@ namespace skiagm {
             return name;
         }
 
-        uint32_t onGetFlags() const SK_OVERRIDE { return kAsBench_Flag | kSkipTiled_Flag; }
+        uint32_t onGetFlags() const SK_OVERRIDE { return kSkipTiled_Flag; }
+        bool runAsBench() const SK_OVERRIDE { return true; }
 
     private:
         typedef GM INHERITED;

gm/variedtext.cpp

@@ -139,8 +139,9 @@ protected:
     uint32_t onGetFlags() const SK_OVERRIDE {
         // The aa hairline stroked rects used to visualize the clip draw slightly differently in
         // quilt mode in dm.
-        return kAsBench_Flag | kSkipTiled_Flag;
+        return kSkipTiled_Flag;
     }
+    bool runAsBench() const SK_OVERRIDE { return true; }
 
 private:
     static const int kCnt = 30;