When skia run bench cases to test performance, it will run constructors for all cases one by one, then getName to skip unnecessary cases according to command line parameters, so these constructors should be lightweight enough to avoid redundant computing. Unfortunately, some constructors contain intensive computing/rendering. They are very heavy, maybe much heavier than need-to-run bench case itself. And these redundant computation will be run every time you run bench, even you just test a single simple case. Moreover, it will mislead the real hotspot/bottleneck of the case itself. 
For example, run a lightweight case, say, region_intersectsrgn_16, the hot spots are gles operation, SuperBlitter, SkRTree... introduced by irrelevant cases' constructors. These redundant computation will mislead performance tuning. 
So we can move these intensive computation to onPreDraw() of these case. They will be executed only if this case should be run.

R=reed@google.com, robertphillips@google.com, humper@google.com, tomhudson@chromium.org

Author: yunchao.he@intel.com

Review URL: https://chromiumcodereview.appspot.com/20997003

git-svn-id: http://skia.googlecode.com/svn/trunk@10486 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/BitmapRectBench.cpp b/bench/BitmapRectBench.cpp
index f9f46b8..c147da2 100644
--- a/bench/BitmapRectBench.cpp
+++ b/bench/BitmapRectBench.cpp
@@ -13,7 +13,7 @@
 #include "SkRandom.h"
 #include "SkString.h"
 
-static void drawIntoBitmap(const SkBitmap& bm) {
+static void draw_into_bitmap(const SkBitmap& bm) {
     const int w = bm.width();
     const int h = bm.height();
 
@@ -45,6 +45,8 @@
     uint8_t     fAlpha;
     SkString    fName;
     SkRect      fSrcR, fDstR;
+    static const int kWidth = 128;
+    static const int kHeight = 128;
     enum { N = SkBENCHLOOP(300) };
 public:
     BitmapRectBench(void* param, U8CPU alpha, bool doFilter, bool slightMatrix) : INHERITED(param) {
@@ -52,37 +54,38 @@
         fDoFilter = doFilter;
         fSlightMatrix = slightMatrix;
 
-        const int w = 128;
-        const int h = 128;
-
-        fBitmap.setConfig(SkBitmap::kARGB_8888_Config, w, h);
-        fBitmap.allocPixels();
-        fBitmap.setIsOpaque(true);
-        fBitmap.eraseColor(SK_ColorBLACK);
-        drawIntoBitmap(fBitmap);
-
-        fSrcR.iset(0, 0, w, h);
-        fDstR.iset(0, 0, w, h);
-
-        if (slightMatrix) {
-            // want fractional translate
-            fDstR.offset(SK_Scalar1 / 3, SK_Scalar1 * 5 / 7);
-            // want enough to create a scale matrix, but not enough to scare
-            // off our sniffer which tries to see if the matrix is "effectively"
-            // translate-only.
-            fDstR.fRight += SK_Scalar1 / (w * 60);
-        }
+        fBitmap.setConfig(SkBitmap::kARGB_8888_Config, kWidth, kHeight);
     }
 
 protected:
-    virtual const char* onGetName() {
+    virtual const char* onGetName() SK_OVERRIDE {
         fName.printf("bitmaprect_%02X_%sfilter_%s",
                      fAlpha, fDoFilter ? "" : "no",
                      fSlightMatrix ? "trans" : "identity");
         return fName.c_str();
     }
 
-    virtual void onDraw(SkCanvas* canvas) {
+    virtual void onPreDraw() SK_OVERRIDE {
+        fBitmap.allocPixels();
+        fBitmap.setIsOpaque(true);
+        fBitmap.eraseColor(SK_ColorBLACK);
+        draw_into_bitmap(fBitmap);
+
+        fSrcR.iset(0, 0, kWidth, kHeight);
+        fDstR.iset(0, 0, kWidth, kHeight);
+
+        if (fSlightMatrix) {
+            // want fractional translate
+            fDstR.offset(SK_Scalar1 / 3, SK_Scalar1 * 5 / 7);
+            // want enough to create a scale matrix, but not enough to scare
+            // off our sniffer which tries to see if the matrix is "effectively"
+            // translate-only.
+            fDstR.fRight += SK_Scalar1 / (kWidth * 60);
+        }
+    }
+
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
         SkRandom rand;
 
         SkPaint paint;
diff --git a/bench/RTreeBench.cpp b/bench/RTreeBench.cpp
index 53dbe28..bce1b67 100644
--- a/bench/RTreeBench.cpp
+++ b/bench/RTreeBench.cpp
@@ -18,7 +18,7 @@
 static const int NUM_QUERY_RECTS = 5000;
 static const int NUM_QUERIES = 1000;
 
-typedef SkIRect (*MakeRectProc)(SkRandom&, int, int);
+typedef SkIRect (*MakeRectProc)(SkMWCRandom&, int, int);
 
 // Time how long it takes to build an R-Tree either bulk-loaded or not
 class BBoxBuildBench : public SkBenchmark {
@@ -41,11 +41,11 @@
         fTree->unref();
     }
 protected:
-    virtual const char* onGetName() {
+    virtual const char* onGetName() SK_OVERRIDE {
         return fName.c_str();
     }
-    virtual void onDraw(SkCanvas* canvas) {
-        SkRandom rand;
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkMWCRandom rand;
         for (int i = 0; i < SkBENCHLOOP(100); ++i) {
             for (int j = 0; j < NUM_BUILD_RECTS; ++j) {
                 fTree->insert(reinterpret_cast<void*>(j), fProc(rand, j, NUM_BUILD_RECTS),
@@ -86,23 +86,26 @@
         if (fBulkLoad) {
             fName.append("_bulk");
         }
-        SkRandom rand;
-        for (int j = 0; j < SkBENCHLOOP(NUM_QUERY_RECTS); ++j) {
-            fTree->insert(reinterpret_cast<void*>(j), fProc(rand, j,
-                           SkBENCHLOOP(NUM_QUERY_RECTS)), fBulkLoad);
-        }
-        fTree->flushDeferredInserts();
         fIsRendering = false;
     }
     virtual ~BBoxQueryBench() {
         fTree->unref();
     }
 protected:
-    virtual const char* onGetName() {
+    virtual const char* onGetName() SK_OVERRIDE {
         return fName.c_str();
     }
-    virtual void onDraw(SkCanvas* canvas) {
-        SkRandom rand;
+    virtual void onPreDraw() SK_OVERRIDE {
+        SkMWCRandom rand;
+        for (int j = 0; j < SkBENCHLOOP(NUM_QUERY_RECTS); ++j) {
+            fTree->insert(reinterpret_cast<void*>(j), fProc(rand, j,
+                           SkBENCHLOOP(NUM_QUERY_RECTS)), fBulkLoad);
+        }
+        fTree->flushDeferredInserts();
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkMWCRandom rand;
         for (int i = 0; i < SkBENCHLOOP(NUM_QUERIES); ++i) {
             SkTDArray<void*> hits;
             SkIRect query;
@@ -145,22 +148,22 @@
     typedef SkBenchmark INHERITED;
 };
 
-static inline SkIRect make_simple_rect(SkRandom&, int index, int numRects) {
+static inline SkIRect make_simple_rect(SkMWCRandom&, int index, int numRects) {
     SkIRect out = {0, 0, GENERATE_EXTENTS, GENERATE_EXTENTS};
     return out;
 }
 
-static inline SkIRect make_concentric_rects_increasing(SkRandom&, int index, int numRects) {
+static inline SkIRect make_concentric_rects_increasing(SkMWCRandom&, int index, int numRects) {
     SkIRect out = {0, 0, index + 1, index + 1};
     return out;
 }
 
-static inline SkIRect make_concentric_rects_decreasing(SkRandom&, int index, int numRects) {
+static inline SkIRect make_concentric_rects_decreasing(SkMWCRandom&, int index, int numRects) {
     SkIRect out = {0, 0, numRects - index, numRects - index};
     return out;
 }
 
-static inline SkIRect make_point_rects(SkRandom& rand, int index, int numRects) {
+static inline SkIRect make_point_rects(SkMWCRandom& rand, int index, int numRects) {
     SkIRect out;
     out.fLeft   = rand.nextU() % GENERATE_EXTENTS;
     out.fTop    = rand.nextU() % GENERATE_EXTENTS;
@@ -169,7 +172,7 @@
     return out;
 }
 
-static inline SkIRect make_random_rects(SkRandom& rand, int index, int numRects) {
+static inline SkIRect make_random_rects(SkMWCRandom& rand, int index, int numRects) {
     SkIRect out;
     out.fLeft   = rand.nextS() % GENERATE_EXTENTS;
     out.fTop    = rand.nextS() % GENERATE_EXTENTS;
@@ -178,7 +181,7 @@
     return out;
 }
 
-static inline SkIRect make_large_rects(SkRandom& rand, int index, int numRects) {
+static inline SkIRect make_large_rects(SkMWCRandom& rand, int index, int numRects) {
     SkIRect out;
     out.fLeft   = rand.nextU() % GENERATE_EXTENTS;
     out.fTop    = rand.nextU() % GENERATE_EXTENTS;
diff --git a/bench/RepeatTileBench.cpp b/bench/RepeatTileBench.cpp
index 11dd6f8..348f906 100644
--- a/bench/RepeatTileBench.cpp
+++ b/bench/RepeatTileBench.cpp
@@ -17,7 +17,7 @@
     "ERROR", "a1", "a8", "index8", "565", "4444", "8888"
 };
 
-static void drawIntoBitmap(const SkBitmap& bm) {
+static void draw_into_bitmap(const SkBitmap& bm) {
     const int w = bm.width();
     const int h = bm.height();
 
@@ -36,32 +36,32 @@
     canvas.drawRect(r, p);
 }
 
-static int conv6ToByte(int x) {
+static int conv_6_to_byte(int x) {
     return x * 0xFF / 5;
 }
 
-static int convByteTo6(int x) {
+static int conv_byte_to_6(int x) {
     return x * 5 / 255;
 }
 
-static uint8_t compute666Index(SkPMColor c) {
+static uint8_t compute_666_index(SkPMColor c) {
     int r = SkGetPackedR32(c);
     int g = SkGetPackedG32(c);
     int b = SkGetPackedB32(c);
 
-    return convByteTo6(r) * 36 + convByteTo6(g) * 6 + convByteTo6(b);
+    return conv_byte_to_6(r) * 36 + conv_byte_to_6(g) * 6 + conv_byte_to_6(b);
 }
 
-static void convertToIndex666(const SkBitmap& src, SkBitmap* dst) {
+static void convert_to_index666(const SkBitmap& src, SkBitmap* dst) {
     SkColorTable* ctable = new SkColorTable(216);
     SkPMColor* colors = ctable->lockColors();
     // rrr ggg bbb
     for (int r = 0; r < 6; r++) {
-        int rr = conv6ToByte(r);
+        int rr = conv_6_to_byte(r);
         for (int g = 0; g < 6; g++) {
-            int gg = conv6ToByte(g);
+            int gg = conv_6_to_byte(g);
             for (int b = 0; b < 6; b++) {
-                int bb = conv6ToByte(b);
+                int bb = conv_6_to_byte(b);
                 *colors++ = SkPreMultiplyARGB(0xFF, rr, gg, bb);
             }
         }
@@ -78,51 +78,60 @@
         const SkPMColor* srcP = src.getAddr32(0, y);
         uint8_t* dstP = dst->getAddr8(0, y);
         for (int x = src.width() - 1; x >= 0; --x) {
-            *dstP++ = compute666Index(*srcP++);
+            *dstP++ = compute_666_index(*srcP++);
         }
     }
 }
 
 class RepeatTileBench : public SkBenchmark {
-    SkPaint     fPaint;
-    SkString    fName;
+    SkPaint          fPaint;
+    SkString         fName;
+    SkBitmap         fBitmap;
+    bool             fIsOpaque;
+    SkBitmap::Config fConfig;
     enum { N = SkBENCHLOOP(20) };
 public:
     RepeatTileBench(void* param, SkBitmap::Config c, bool isOpaque = false) : INHERITED(param) {
         const int w = 50;
         const int h = 50;
-        SkBitmap bm;
+        fConfig = c;
+        fIsOpaque = isOpaque;
 
-        if (SkBitmap::kIndex8_Config == c) {
-            bm.setConfig(SkBitmap::kARGB_8888_Config, w, h);
+        if (SkBitmap::kIndex8_Config == fConfig) {
+            fBitmap.setConfig(SkBitmap::kARGB_8888_Config, w, h);
         } else {
-            bm.setConfig(c, w, h);
+            fBitmap.setConfig(fConfig, w, h);
         }
-        bm.allocPixels();
-        bm.eraseColor(isOpaque ? SK_ColorWHITE : 0);
-        bm.setIsOpaque(isOpaque);
-
-        drawIntoBitmap(bm);
-
-        if (SkBitmap::kIndex8_Config == c) {
-            SkBitmap tmp;
-            convertToIndex666(bm, &tmp);
-            bm = tmp;
-        }
-
-        SkShader* s = SkShader::CreateBitmapShader(bm,
-                                                   SkShader::kRepeat_TileMode,
-                                                   SkShader::kRepeat_TileMode);
-        fPaint.setShader(s)->unref();
-        fName.printf("repeatTile_%s_%c", gConfigName[bm.config()], isOpaque ? 'X' : 'A');
+        fName.printf("repeatTile_%s_%c",
+                     gConfigName[fBitmap.config()], isOpaque ? 'X' : 'A');
     }
 
 protected:
-    virtual const char* onGetName() {
+    virtual const char* onGetName() SK_OVERRIDE {
         return fName.c_str();
     }
 
-    virtual void onDraw(SkCanvas* canvas) {
+    virtual void onPreDraw() SK_OVERRIDE {
+        fBitmap.allocPixels();
+        fBitmap.eraseColor(fIsOpaque ? SK_ColorWHITE : 0);
+        fBitmap.setIsOpaque(fIsOpaque);
+
+        draw_into_bitmap(fBitmap);
+
+        if (SkBitmap::kIndex8_Config == fConfig) {
+            SkBitmap tmp;
+            convert_to_index666(fBitmap, &tmp);
+            fBitmap = tmp;
+        }
+
+        SkShader* s = SkShader::CreateBitmapShader(fBitmap,
+                                                   SkShader::kRepeat_TileMode,
+                                                   SkShader::kRepeat_TileMode);
+        fPaint.setShader(s)->unref();
+    }
+
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
         SkPaint paint(fPaint);
         this->setupPaint(&paint);