Add high resolution WallTimer to SampleApp

Gives better than 1 ms results when timing framerate.

Review URL: https://codereview.chromium.org/1288473002

2 files changed, 9 insertions, 8 deletions

diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index 486feedb79..5bb223a312 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -1313,8 +1313,9 @@ void SampleWindow::afterChildren(SkCanvas* orig) {
     }
 
     // Do this after presentGL and other finishing, rather than in afterChild
-    if (fMeasureFPS && fMeasureFPS_StartTime) {
-        fMeasureFPS_Time += SkTime::GetMSecs() - fMeasureFPS_StartTime;
+    if (fMeasureFPS) {
+        fTimer.end();
+        fMeasureFPS_Time += fTimer.fWall;
     }
 }
 
@@ -1351,9 +1352,8 @@ void SampleWindow::beforeChild(SkView* child, SkCanvas* canvas) {
     }
 
     if (fMeasureFPS) {
-        if (SampleView::SetRepeatDraw(child, FPS_REPEAT_COUNT)) {
-            fMeasureFPS_StartTime = SkTime::GetMSecs();
-        }
+        (void)SampleView::SetRepeatDraw(child, FPS_REPEAT_COUNT);
+        fTimer.start();
     } else {
         (void)SampleView::SetRepeatDraw(child, 1);
     }
@@ -1935,7 +1935,7 @@ void SampleWindow::updateTitle() {
     }
 
     if (fMeasureFPS) {
-        title.appendf(" %8.3f ms", fMeasureFPS_Time / (float)FPS_REPEAT_COUNT);
+        title.appendf(" %8.4f ms", fMeasureFPS_Time / (float)FPS_REPEAT_COUNT);
     }
 
     SkView* view = curr_view(this);
diff --git a/samplecode/SampleApp.h b/samplecode/SampleApp.h
index 97854fcb97..c0f845d32c 100644
--- a/samplecode/SampleApp.h
+++ b/samplecode/SampleApp.h
@@ -16,6 +16,7 @@
 #include "SkTDArray.h"
 #include "SkTouchGesture.h"
 #include "SkWindow.h"
+#include "timer/Timer.h"
 
 class GrContext;
 class GrRenderTarget;
@@ -183,8 +184,8 @@ private:
     bool fPerspAnim;
     bool fRequestGrabImage;
     bool fMeasureFPS;
-    SkMSec fMeasureFPS_Time;
-    SkMSec fMeasureFPS_StartTime;
+    WallTimer fTimer;
+    double fMeasureFPS_Time;
     bool fMagnify;
     int fTilingMode;