Fix clang 'overloaded-virtual' warnings.

This patch fixes the warning like the following:

../../src/animator/SkPaintParts.h:26:18: warning: 'SkPaintPart::add' hides overloaded virtual function [-Woverloaded-virtual]
virtual bool add() = 0;
             ^
../../src/animator/SkDisplayable.h:35:18: note: hidden overloaded virtual function 'SkDisplayable::add' declared here
virtual bool add(SkAnimateMaker& , SkDisplayable* child);
             ^

R=robertphillips@google.com,

Review URL: https://codereview.appspot.com/6843134

git-svn-id: http://skia.googlecode.com/svn/trunk@6642 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/animator/SkDrawExtraPathEffect.cpp b/src/animator/SkDrawExtraPathEffect.cpp
index 65d9cba..ef6ef28 100644
--- a/src/animator/SkDrawExtraPathEffect.cpp
+++ b/src/animator/SkDrawExtraPathEffect.cpp
@@ -22,7 +22,7 @@
     DECLARE_PRIVATE_MEMBER_INFO(DrawShapePathEffect);
     SkDrawShapePathEffect();
     virtual ~SkDrawShapePathEffect();
-    virtual bool add(SkAnimateMaker& , SkDisplayable* ) SK_OVERRIDE;
+    virtual bool addChild(SkAnimateMaker& , SkDisplayable* ) SK_OVERRIDE;
     virtual SkPathEffect* getPathEffect();
 protected:
     SkDrawable* addPath;
@@ -60,7 +60,7 @@
     DECLARE_EXTRAS_MEMBER_INFO(SkDrawComposePathEffect);
     SkDrawComposePathEffect(SkDisplayTypes );
     virtual ~SkDrawComposePathEffect();
-    virtual bool add(SkAnimateMaker& , SkDisplayable* ) SK_OVERRIDE;
+    virtual bool addChild(SkAnimateMaker& , SkDisplayable* ) SK_OVERRIDE;
     virtual SkPathEffect* getPathEffect();
     virtual bool isPaint() const;
 private:
@@ -184,7 +184,7 @@
     SkSafeUnref(fPathEffect);
 }
 
-bool SkDrawShapePathEffect::add(SkAnimateMaker& , SkDisplayable* child) {
+bool SkDrawShapePathEffect::addChild(SkAnimateMaker& , SkDisplayable* child) {
     path = (SkDrawPath*) child;
     return true;
 }
@@ -354,7 +354,7 @@
     delete effect2;
 }
 
-bool SkDrawComposePathEffect::add(SkAnimateMaker& , SkDisplayable* child) {
+bool SkDrawComposePathEffect::addChild(SkAnimateMaker& , SkDisplayable* child) {
     if (effect1 == NULL)
         effect1 = (SkDrawPathEffect*) child;
     else