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

5 files changed, 26 insertions, 23 deletions

diff --git a/include/animator/SkAnimator.h b/include/animator/SkAnimator.h
index 9bb3642ca0..0fe787c526 100644
--- a/include/animator/SkAnimator.h
+++ b/include/animator/SkAnimator.h
@@ -443,7 +443,8 @@ public:
     };
 
     /** Sets a user class to return the current time to the animator.
-        Optional; if not called, the system clock will be used by calling SkTime::GetMSecs instead.
+        Optional; if not called, the system clock will be used by calling
+        SkEvent::GetMSecsSinceStartup instead.
         @param callBack the time function
     */
     void setTimeline(const Timeline& );
diff --git a/include/core/SkTime.h b/include/core/SkTime.h
index 3ff29aa25e..8a8224a82a 100644
--- a/include/core/SkTime.h
+++ b/include/core/SkTime.h
@@ -34,34 +34,27 @@ public:
     };
     static void GetDateTime(DateTime*);
 
-    static SkMSec GetMSecs() { return (SkMSec)(GetNSecs() * 1e-6); }
+    static double GetSecs() { return GetNSecs() * 1e-9; }
+    static double GetMSecs() { return GetNSecs() * 1e-6; }
     static double GetNSecs();
 };
 
-#define SK_TIME_FACTOR      1
-
 ///////////////////////////////////////////////////////////////////////////////
 
 class SkAutoTime {
 public:
     // The label is not deep-copied, so its address must remain valid for the
     // lifetime of this object
-    SkAutoTime(const char* label = NULL, SkMSec minToDump = 0) : fLabel(label)
-    {
-        fNow = SkTime::GetMSecs();
-        fMinToDump = minToDump;
-    }
-    ~SkAutoTime()
-    {
-        SkMSec dur = SkTime::GetMSecs() - fNow;
-        if (dur >= fMinToDump) {
-            SkDebugf("%s %d\n", fLabel ? fLabel : "", dur);
-        }
+    SkAutoTime(const char* label = nullptr)
+        : fLabel(label)
+        , fNow(SkTime::GetMSecs()) {}
+    ~SkAutoTime() {
+        uint64_t dur = static_cast<uint64_t>(SkTime::GetMSecs() - fNow);
+        SkDebugf("%s %ld\n", fLabel ? fLabel : "", dur);
     }
 private:
     const char* fLabel;
-    SkMSec      fNow;
-    SkMSec      fMinToDump;
+    double      fNow;
 };
 #define SkAutoTime(...) SK_REQUIRE_LOCAL_VAR(SkAutoTime)
 
diff --git a/include/core/SkTypes.h b/include/core/SkTypes.h
index d7a791163b..a94a59233f 100644
--- a/include/core/SkTypes.h
+++ b/include/core/SkTypes.h
@@ -342,13 +342,15 @@ typedef uint32_t SkFourByteTag;
 /** 32 bit integer to hold a unicode value
 */
 typedef int32_t SkUnichar;
-/** 32 bit value to hold a millisecond count
-*/
+
+/** 32 bit value to hold a millisecond duration
+ *  Note that SK_MSecMax is about 25 days.
+ */
 typedef uint32_t SkMSec;
 /** 1 second measured in milliseconds
 */
 #define SK_MSec1 1000
-/** maximum representable milliseconds
+/** maximum representable milliseconds; 24d 20h 31m 23.647s.
 */
 #define SK_MSecMax 0x7FFFFFFF
 /** Returns a < b for milliseconds, correctly handling wrap-around from 0xFFFFFFFF to 0
diff --git a/include/views/SkEvent.h b/include/views/SkEvent.h
index 0af76fe686..b8fc00ef51 100644
--- a/include/views/SkEvent.h
+++ b/include/views/SkEvent.h
@@ -206,13 +206,20 @@ public:
     /**
      *  Post to the event queue using the event's targetID or target-proc.
      *  The event will be delivered no sooner than the specified millisecond
-     *  time, as measured by SkTime::GetMSecs().
+     *  time, as measured by GetMSecsSinceStartup().
      *
      *  The event must be dynamically allocated, as ownership is transferred to
      *  the event queue. It cannot be allocated on the stack or in a global.
      */
     void postTime(SkMSec time);
 
+    /**
+     *  Returns ~zero the first time it's called, then returns the number of
+     *  milliseconds since the first call. Behavior is undefined if the program
+     *  runs more than ~25 days.
+     */
+    static SkMSec GetMSecsSinceStartup();
+
     ///////////////////////////////////////////////
     /** Porting layer must call these functions **/
     ///////////////////////////////////////////////
diff --git a/include/views/SkTouchGesture.h b/include/views/SkTouchGesture.h
index 4a03065e25..60487c7a2f 100644
--- a/include/views/SkTouchGesture.h
+++ b/include/views/SkTouchGesture.h
@@ -55,14 +55,14 @@ private:
         float   fStartX, fStartY;
         float   fPrevX, fPrevY;
         float   fLastX, fLastY;
-        SkMSec  fPrevT, fLastT;
+        float   fPrevT, fLastT;
     };
     SkTDArray<Rec> fTouches;
 
     State           fState;
     SkMatrix        fLocalM, fGlobalM;
     SkFlingState    fFlinger;
-    SkMSec          fLastUpT;
+    double          fLastUpMillis;
     SkPoint         fLastUpP;