Drive SVG Animations via requestAnimationFrame

Source/core/svg/graphics/SVGImageChromeClient.cpp

Index: Source/core/svg/graphics/SVGImageChromeClient.cpp
diff --git a/Source/core/svg/graphics/SVGImageChromeClient.cpp b/Source/core/svg/graphics/SVGImageChromeClient.cpp
index 5c197ba7fcf80d6b68facd3ac5cd9a9aaf87c28e..290c821eb986a4ccaad5bf1b0fd24e84d55ad9ce 100644
--- a/Source/core/svg/graphics/SVGImageChromeClient.cpp
+++ b/Source/core/svg/graphics/SVGImageChromeClient.cpp
@@ -35,6 +35,8 @@
 
 namespace WebCore {
 
+static const double animationFrameDelay = 0.025;

[dstockwell, 2014/03/04 01:19:04]

Is this 40hz, why?

[fs, 2014/03/04 10:28:19]

I used the old value from the SVG animations code here. (To try and avoid
changing too much in one go.) I don't feel strongly about the exact value though
(and would of course rather sync this with some clock, but that's not how
animated Images work in general, and we don't really have anything to key off in
this context.)

+
 SVGImageChromeClient::SVGImageChromeClient(SVGImage* image)
     : m_image(image)
     , m_animationTimer(this, &SVGImageChromeClient::animationTimerFired)
@@ -67,7 +69,12 @@ void SVGImageChromeClient::scheduleAnimation()
     // approach.
     if (m_animationTimer.isActive())
         return;
-    m_animationTimer.startOneShot(0);
+    // Schedule the 'animation' ASAP if the image does not contain any
+    // animations, but prefer a fixed, jittery, frame-delay if there're any
+    // animations. Checking for pending/active animations could be more
+    // stringent.
+    double fireTime = m_image->hasAnimations() ? animationFrameDelay : 0;
+    m_animationTimer.startOneShot(fireTime);
 }
 
 void SVGImageChromeClient::animationTimerFired(Timer<SVGImageChromeClient>*)