Add query for block dimensions of a given format

src/opts/SkTextureCompression_opts_arm.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTextureCompression_opts.h"
 #include "SkTextureCompression_opts_neon.h"
 #include "SkUtilsArm.h"
@@ skipping 18 matching lines @@
                     return NULL;
             }
         }
         break;
 
         default:
             return NULL;
     }
 #endif
 }
+
+bool SkTextureCompressorGetPlatformDims(SkTextureCompressor::Format fmt, int* dimX, int* dimY) {
+#if SK_ARM_NEON_IS_NONE
+    return false;
+#else
+#if SK_ARM_NEON_IS_DYNAMIC
+    if (!sk_cpu_arm_has_neon()) {
+        return false;
+    }
+#endif
+    switch (fmt) {
+        case SkTextureCompressor::kR11_EAC_Format:
+            *dimX = 16;
+            *dimY = 4;
+            return true;
+        default:
+            return false;
+    }
+    return false;
+#endif
+}