Change SkTime::GetMSecs to double; ensure values stored in SkMSec do not overflow.

tests/SkpSkGrTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrContext.h"
 #include "GrContextFactory.h"
 #include "GrRenderTarget.h"
@@ skipping 88 matching lines @@
         strcpy(fFilename, filename.c_str());
         testOne();
     }
 
     void testOne();
 
     char fFilename[kMaxLength];
     TestStep fTestStep;
     int fDirNo;
     int fPixelError;
-    int fTime;
+    SkMSec fTime;
     bool fScaleOversized;
 };
 
 struct SkpSkGrThreadState {
     void init(int dirNo) {
         fResult.init(dirNo);
         fFoundCount = 0;
         fSmallestError = 0;
         sk_bzero(fFilesFound, sizeof(fFilesFound));
         sk_bzero(fDirsFound, sizeof(fDirsFound));
@@ skipping 216 matching lines @@
     canvas->save();
     int pWidth = pic->width();
     int pHeight = pic->height();
     const int maxDimension = 1000;
     const int slices = 3;
     int xInterval = SkTMax(pWidth - maxDimension, 0) / (slices - 1);
     int yInterval = SkTMax(pHeight - maxDimension, 0) / (slices - 1);
     SkRect rect = {0, 0, SkIntToScalar(SkTMin(maxDimension, pWidth)),
             SkIntToScalar(SkTMin(maxDimension, pHeight))};
     canvas->clipRect(rect);
-    SkMSec start = SkTime::GetMSecs();
+    skiatest::Timer timer;
     for (int x = 0; x < slices; ++x) {
         for (int y = 0; y < slices; ++y) {
             pic->draw(canvas);
             canvas->translate(0, SkIntToScalar(yInterval));
         }
         canvas->translate(SkIntToScalar(xInterval), SkIntToScalar(-yInterval * slices));
     }
-    SkMSec end = SkTime::GetMSecs();
+    SkMSec elapsed = timer.elapsedMsInt();
     canvas->restore();
-    return end - start;
+    return elapsed;
 }
 
 static void drawPict(SkPicture* pic, SkCanvas* canvas, int scale) {
     canvas->clear(SK_ColorWHITE);
     if (scale != 1) {
         canvas->save();
         canvas->scale(1.0f / scale, 1.0f / scale);
     }
     pic->draw(canvas);
     if (scale != 1) {
@@ skipping 88 matching lines @@
         SkGpuDevice grDevice(context, texture.get());
         SkCanvas grCanvas(&grDevice);
         drawPict(pic.get(), &grCanvas, fScaleOversized ? scale : 1);
 
         SkBitmap grBitmap;
         grBitmap.allocPixels(grCanvas.imageInfo());
         grCanvas.readPixels(&grBitmap, 0, 0);
 
         if (fTestStep == kCompareBits) {
             fPixelError = similarBits(grBitmap, bitmap);
-            int skTime = timePict(pic, &skCanvas);
-            int grTime = timePict(pic, &grCanvas);
+            SkMSec skTime = timePict(pic, &skCanvas);
+            SkMSec grTime = timePict(pic, &grCanvas);
             fTime = skTime - grTime;
         } else if (fTestStep == kEncodeFiles) {
             SkString pngStr = make_png_name(fFilename);
             const char* pngName = pngStr.c_str();
             writePict(grBitmap, outGrDir, pngName);
             writePict(bitmap, outSkDir, pngName);
         }
     }
 }
 
@@ skipping 268 matching lines @@
     int testIndex = 166;
     int dirIndex = skipOverSkGr[testIndex - 166].directory;
     SkString pictDir = make_in_dir_name(dirIndex);
     if (pictDir.size() == 0) {
         return;
     }
     SkString filename(skipOverSkGr[testIndex - 166].filename);
     TestResult::Test(dirIndex, filename.c_str(), kCompareBits, reporter->verbose());
     TestResult::Test(dirIndex, filename.c_str(), kEncodeFiles, reporter->verbose());
 }