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/SkDrawGroup.cpp b/src/animator/SkDrawGroup.cpp
index 806da5e..ddd23d3 100644
--- a/src/animator/SkDrawGroup.cpp
+++ b/src/animator/SkDrawGroup.cpp
@@ -49,7 +49,7 @@
     }
 }
 
-bool SkGroup::add(SkAnimateMaker& , SkDisplayable* child) {
+bool SkGroup::addChild(SkAnimateMaker& , SkDisplayable* child) {
     SkASSERT(child);
 //  SkASSERT(child->isDrawable());
     *fChildren.append() = (SkDrawable*) child;
@@ -86,7 +86,7 @@
     for (SkDrawable** ptr = fChildren.begin(); ptr < fChildren.end(); ptr++) {
         SkDisplayable* displayable = (SkDisplayable*)*ptr;
         SkDisplayable* deeperCopy = displayable->deepCopy(maker);
-        ((SkGroup*)copy)->add(*maker, deeperCopy);
+        ((SkGroup*)copy)->addChild(*maker, deeperCopy);
     }
     return copy;
 }