Fix compile errors in ViE with latest clang.

Rolling to the latest Chromium picks up a new clang, which catches a fresh error:

error: 'reinterpret_cast' to class 'webrtc::VideoEngineImpl *' from its base at non-zero offset 'webrtc::VideoEngine *' behaves differently from 'static_cast' [-Werror,-Wreinterpret-base-class]
 VideoEngineImpl* vie_impl = reinterpret_cast<VideoEngineImpl*>(video_engine);
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../webrtc/video_engine/vie_codec_impl.cc:36:31: note: use 'static_cast' to adjust the pointer correctly while downcasting
  VideoEngineImpl* vie_impl = reinterpret_cast<VideoEngineImpl*>(video_engine);
                              ^~~~~~~~~~~~~~~~
                              static_cast

This was triggered by André's change here:
https://code.google.com/p/webrtc/source/detail?r=3986
which made VideoEngineImpl a derived class of VideoEngine (good).

Picked up one other error as well:
error: implicit conversion from 'long' to 'int' changes value from 9223372036854775807 to -1 [-Werror,-Wconstant-conversion]
        AutoTestSleep(std::numeric_limits<long>::max());
        ~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This fixes the errors and is required before stable can be rolled in Chromium.

TBR=mflodman,andresp

Review URL: https://webrtc-codereview.appspot.com/1450004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3989 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/video_engine/vie_codec_impl.cc b/video_engine/vie_codec_impl.cc
index 67ac417..77b4d89 100644
--- a/video_engine/vie_codec_impl.cc
+++ b/video_engine/vie_codec_impl.cc
@@ -33,7 +33,7 @@
   if (!video_engine) {
     return NULL;
   }
-  VideoEngineImpl* vie_impl = reinterpret_cast<VideoEngineImpl*>(video_engine);
+  VideoEngineImpl* vie_impl = static_cast<VideoEngineImpl*>(video_engine);
   ViECodecImpl* vie_codec_impl = vie_impl;
   // Increase ref count.
   (*vie_codec_impl)++;