Bug 758505, Part 3: Avoid unnecessary invalidations on repeated calls to set the same animated value (for SMIL animations of CSS, mapped attrs, and motion). r=dholbert

content/smil/nsSMILCSSProperty.cpp

@@ -166,6 +166,11 @@ nsSMILCSSProperty::SetAnimValue(const nsSMILValue& aValue)
   nsCOMPtr<nsICSSDeclaration> overrideDecl =
     do_QueryInterface(mElement->GetSMILOverrideStyle());
   if (overrideDecl) {
+    nsAutoString oldValStr;
+    overrideDecl->GetPropertyValue(mPropID, oldValStr);
+    if (valStr.Equals(oldValStr)) {
+      return NS_OK;
+    }
     overrideDecl->SetPropertyValue(mPropID, valStr);
   }
   return NS_OK;

content/smil/nsSMILMappedAttribute.cpp

@@ -5,6 +5,7 @@
 
 /* representation of a SMIL-animatable mapped attribute on an element */
 #include "nsSMILMappedAttribute.h"
+#include "nsAttrValue.h"
 #include "nsPropertyTable.h"
 #include "nsContentErrors.h" // For NS_PROPTABLE_PROP_OVERWRITTEN
 #include "nsSMILValue.h"
@@ -92,10 +93,16 @@ nsSMILMappedAttribute::SetAnimValue(const nsSMILValue& aValue)
     return NS_ERROR_FAILURE;
   }
 
+  nsRefPtr<nsIAtom> attrName = GetAttrNameAtom();
+  nsStringBuffer* oldValStrBuf = static_cast<nsStringBuffer*>
+    (mElement->GetProperty(SMIL_MAPPED_ATTR_ANIMVAL, attrName));
+  if (oldValStrBuf && valStr.Equals(nsCheapString(oldValStrBuf))) {
+    return NS_OK;
+  }
+
   // Set the string as this mapped attribute's animated value.
   nsStringBuffer* valStrBuf =
     nsCSSValue::BufferFromString(nsString(valStr)).get();
-  nsRefPtr<nsIAtom> attrName = GetAttrNameAtom();
   nsresult rv = mElement->SetProperty(SMIL_MAPPED_ATTR_ANIMVAL,
                                       attrName, valStrBuf,
                                       ReleaseStringBufferPropertyValue);

content/svg/content/src/nsSVGGraphicElement.cpp

@@ -229,6 +229,10 @@ nsSVGGraphicElement::PrependLocalTransformsTo(const gfxMatrix &aMatrix,
 void
 nsSVGGraphicElement::SetAnimateMotionTransform(const gfxMatrix* aMatrix)
 {
+  if ((!aMatrix && !mAnimateMotionTransform) ||
+      aMatrix && mAnimateMotionTransform && *aMatrix == *mAnimateMotionTransform) {
+    return;
+  }
   mAnimateMotionTransform = aMatrix ? new gfxMatrix(*aMatrix) : nsnull;
   DidAnimateTransformList();
 }

gfx/thebes/gfxMatrix.h

@@ -65,6 +65,21 @@ public:
         return gfxMatrix(*this).Multiply(m);
     }
 
+    /* Returns true if the other matrix is fuzzy-equal to this matrix.
+     * Note that this isn't a cheap comparison!
+     */
+    bool operator==(const gfxMatrix& other) const
+    {
+      return FuzzyEqual(xx, other.xx) && FuzzyEqual(yx, other.yx) &&
+             FuzzyEqual(xy, other.xy) && FuzzyEqual(yy, other.yy) &&
+             FuzzyEqual(x0, other.x0) && FuzzyEqual(y0, other.y0);
+    }
+
+    bool operator!=(const gfxMatrix& other) const
+    {
+      return !(*this == other);
+    }
+
     // matrix operations
     /**
      * Resets this matrix to the identity matrix.