Enable and fix chromium clang warnings in sdk/android targets.

Targets:
base_jni, internal_jni, video_jni, vp8_jni and vp9_jni

Bug: webrtc:163
Change-Id: I4aa68c81e6e7cbe5fdf78c90e464b46c55633252
Reviewed-on: https://webrtc-review.googlesource.com/66820
Commit-Queue: Paulina Hensman <phensman@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22744}

modules/video_coding/codecs/vp8/include/vp8.h

@@ -23,14 +23,14 @@ class VP8Encoder : public VideoEncoder {
  public:
   static std::unique_ptr<VP8Encoder> Create();
 
-  virtual ~VP8Encoder() {}
+  ~VP8Encoder() override {}
 };  // end of VP8Encoder class
 
 class VP8Decoder : public VideoDecoder {
  public:
   static std::unique_ptr<VP8Decoder> Create();
 
-  virtual ~VP8Decoder() {}
+  ~VP8Decoder() override {}
 };  // end of VP8Decoder class
 }  // namespace webrtc
 

modules/video_coding/codecs/vp9/include/vp9.h

@@ -23,7 +23,7 @@ class VP9Encoder : public VideoEncoder {
   static bool IsSupported();
   static std::unique_ptr<VP9Encoder> Create();
 
-  virtual ~VP9Encoder() {}
+  ~VP9Encoder() override {}
 };
 
 class VP9Decoder : public VideoDecoder {
@@ -31,7 +31,7 @@ class VP9Decoder : public VideoDecoder {
   static bool IsSupported();
   static std::unique_ptr<VP9Decoder> Create();
 
-  virtual ~VP9Decoder() {}
+  ~VP9Decoder() override {}
 };
 }  // namespace webrtc
 

modules/video_coding/utility/moving_average.cc

@@ -15,6 +15,7 @@
 namespace webrtc {
 
 MovingAverage::MovingAverage(size_t s) : sum_history_(s + 1, 0) {}
+MovingAverage::~MovingAverage() = default;
 
 void MovingAverage::AddSample(int sample) {
   count_++;

modules/video_coding/utility/moving_average.h

@@ -19,6 +19,7 @@ namespace webrtc {
 class MovingAverage {
  public:
   explicit MovingAverage(size_t s);
+  ~MovingAverage();
   void AddSample(int sample);
   rtc::Optional<int> GetAverage() const;
   rtc::Optional<int> GetAverage(size_t num_samples) const;