Code cleanup: Replace Element with Document in element.animate()

third_party/WebKit/Source/core/animation/AnimationEffectTiming.cpp

Index: third_party/WebKit/Source/core/animation/AnimationEffectTiming.cpp
diff --git a/third_party/WebKit/Source/core/animation/AnimationEffectTiming.cpp b/third_party/WebKit/Source/core/animation/AnimationEffectTiming.cpp
index f95a7b5a1542491371b1812ea5c3147a8272b7ca..ff063821247b43165ecaf26c7c290ade131cafa7 100644
--- a/third_party/WebKit/Source/core/animation/AnimationEffectTiming.cpp
+++ b/third_party/WebKit/Source/core/animation/AnimationEffectTiming.cpp
@@ -8,6 +8,7 @@
 #include "bindings/core/v8/UnrestrictedDoubleOrString.h"
 #include "core/animation/AnimationEffect.h"
 #include "core/animation/KeyframeEffect.h"
+#include "core/dom/Document.h"
 #include "platform/animation/TimingFunction.h"
 
 namespace blink {
@@ -126,15 +127,10 @@ void AnimationEffectTiming::setDirection(String direction)
     m_parent->updateSpecifiedTiming(timing);
 }
 
-void AnimationEffectTiming::setEasing(String easing, ExceptionState& exceptionState)
+void AnimationEffectTiming::setEasing(ExecutionContext* executionContext, String easing, ExceptionState& exceptionState)
 {
     Timing timing = m_parent->specifiedTiming();
-    // The AnimationEffectTiming might not be attached to a document at this
-    // point, so we pass nullptr in to setTimingFunction. This means that these
-    // calls are not considered in the WebAnimationsEasingAsFunction*
-    // UseCounters, but the bug we are tracking there does not come through
-    // this interface.
-    if (TimingInput::setTimingFunction(timing, easing, nullptr, exceptionState))
+    if (TimingInput::setTimingFunction(timing, easing, toDocument(*executionContext), exceptionState))

[suzyh_UTC10 (ex-contributor), 2016/07/07 05:59:44]

Could the toDocument conversion here ever fail, or not make sense for some other
reason? Also, what if the ExecutionContext is null?

My best guess is that this function is currently only called by the
AnimationEffectTiming generated code, and as a result will only be called with a
document as the ExecutionContext. However it's not clear to me that it is
impossible for other code to be written that passes in a different kind of
ExecutionContext.


... And I think your third patchset illustrates my concern. There needs to be
some kind of error checking here and in KeyframeEffect.cpp to prevent crashes
(or give informative/targeted error messages on crashes) in that event.

         m_parent->updateSpecifiedTiming(timing);
 }