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

The following are currently unused in Android, Google3, Chromium, and Mozilla:
  - SkEvent
  - SkTime::GetMSecs
  - SK_TIME_FACTOR (also unused in Skia)
  - SkAutoTime

I left uses of SkMSec more-or-less intact for SkEvent, SkAnimator, and SkInterpolator. SkInterpolator is used in Chromium, so I did not want to change the API. The views/ and animator/ code is crufty, so it didn't seem worthwhile to refactor it. Instead, I added SkEvent::GetMSecsSinceStartup, which is likely to be adequate for use in SampleApp.

I also left SkMSec where it is used to measure a duration rather than a timestamp. With the exception of SkMovie, which is used in Android, all of the uses appear to measure the execution time of a piece of code, which I would hope does not exceed 2^31 milliseconds.

Added skiatest::Timer to support a common idiom in tests where we want to measure the wallclock time in integer milliseconds. (Not used in tests/PathOpsSkpClipTest.cpp because it redefines things in Test.h.)

Removed tabs in tests/StrokerTest.cpp.

BUG=skia:4632
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1811613004

Review URL: https://codereview.chromium.org/1811613004

1 files changed, 21 insertions, 0 deletions

diff --git a/tests/Test.h b/tests/Test.h
index d643c8382a..411ce11c20 100644
--- a/tests/Test.h
+++ b/tests/Test.h
@@ -85,6 +85,27 @@ enum GPUTestContexts {
 template<typename T>
 void RunWithGPUTestContexts(T testFunction, GPUTestContexts contexts, Reporter* reporter,
                             GrContextFactory* factory);
+
+/** Timer provides wall-clock duration since its creation. */
+class Timer {
+public:
+    /** Starts the timer. */
+    Timer();
+
+    /** Nanoseconds since creation. */
+    double elapsedNs() const;
+
+    /** Milliseconds since creation. */
+    double elapsedMs() const;
+
+    /** Milliseconds since creation as an integer.
+        Behavior is undefined for durations longer than SK_MSecMax.
+    */
+    SkMSec elapsedMsInt() const;
+private:
+    double fStartNanos;
+};
+
 }  // namespace skiatest
 
 #define REPORTER_ASSERT(r, cond)                  \