Don't paint SVG image documents unless actually painting.

third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp

Index: third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
diff --git a/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp b/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
index 3b2c12117c1664908b8b3c39fa28fe73f6f9311d..819ecd92d85c3e4cc926c3e8c95937bc84eea316 100644
--- a/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
+++ b/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
@@ -491,8 +491,13 @@ void SVGImage::serviceAnimations(double monotonicAnimationStartTime) {
   // that will keep the associated SVGImageChromeClient object alive.
   Persistent<ImageObserver> protect(getImageObserver());
   m_page->animator().serviceScriptedAnimations(monotonicAnimationStartTime);
-  m_page->animator().updateAllLifecyclePhases(
-      *toLocalFrame(m_page->mainFrame()));
+  // Do *not* update the paint phase. It's critical to paint only when
+  // actually generating painted output, not only for performance reasons,
+  // but to preserve correct coherence of the cache of the output with
+  // the needsRepaint bits of the PaintLayers in the image.
+  toLocalFrame(m_page->mainFrame())
+      ->view()
+      ->updateAllLifecyclePhasesExceptPaint();
 }
 
 void SVGImage::advanceAnimationForTesting() {