Add return to SkBoxBlurGetPlatformProcs_SSE4.

src/opts/SkBlurImage_opts_SSE4.cpp

 /*
  * Copyright 2014 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkBlurImage_opts_SSE4.h"
 #include "SkColorPriv.h"
@@ skipping 99 matching lines @@
     return true;
 }
 
 #else // !defined(SK_BUILD_FOR_ANDROID_FRAMEWORK) || SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE41
 
 bool SkBoxBlurGetPlatformProcs_SSE4(SkBoxBlurProc* boxBlurX,
                                     SkBoxBlurProc* boxBlurY,
                                     SkBoxBlurProc* boxBlurXY,
                                     SkBoxBlurProc* boxBlurYX) {
     sk_throw();
+    return false;
 }
 
 
 #endif