SkTDynamicHash: remove need for Equals(const T&, const Key&) param.

All implementations are relying on bool operator==(const Key&, const Key&)
anyway, which makes total sense, so just make that required.

BUG=skia:
R=bsalomon@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/222343002

git-svn-id: http://skia.googlecode.com/svn/trunk@14027 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkScaledImageCache.cpp b/src/core/SkScaledImageCache.cpp
index c436417..8320b92 100644
--- a/src/core/SkScaledImageCache.cpp
+++ b/src/core/SkScaledImageCache.cpp
@@ -144,16 +144,13 @@
     return key.fHash;
 }
 
-bool eq_rec_key(const SkScaledImageCache::Rec& rec, const SkScaledImageCache::Key& key) {
-    return rec.fKey == key;
-}
-}
+}  // namespace
 
 class SkScaledImageCache::Hash : public SkTDynamicHash<SkScaledImageCache::Rec,
                                                        SkScaledImageCache::Key,
                                                        key_from_rec,
-                                                       hash_from_key,
-                                                       eq_rec_key> {};
+                                                       hash_from_key> {};
+
 
 ///////////////////////////////////////////////////////////////////////////////