Revert of Combine webrtc/api/java/android and webrtc/api/java/src. (patchset #1 id:1 of https://codereview.webrtc.org/2111823002/ )

Reason for revert:
Breaks downstream dependencies

Original issue's description:
> Combine webrtc/api/java/android and webrtc/api/java/src.
>
> It used to be that there was a Java api for devices not running Android
> but that is no longer the case. I combined the directories and made
> the folder structure chromium style.
>
> BUG=webrtc:6067
> R=magjed@webrtc.org, tommi@webrtc.org
>
> Committed: https://chromium.googlesource.com/external/webrtc/+/ceefe20dd65387d83059d9fc1ce84842650ed5e2

TBR=magjed@webrtc.org,tommi@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6067

Review URL: https://codereview.webrtc.org/2106333005 .

Cr-Commit-Position: refs/heads/master@{#13357}
diff --git a/webrtc/api/java/jni/native_handle_impl.cc b/webrtc/api/java/jni/native_handle_impl.cc
new file mode 100644
index 0000000..eb71088
--- /dev/null
+++ b/webrtc/api/java/jni/native_handle_impl.cc
@@ -0,0 +1,215 @@
+/*
+ *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/api/java/jni/native_handle_impl.h"
+
+#include <memory>
+
+#include "webrtc/api/java/jni/jni_helpers.h"
+#include "webrtc/base/bind.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/keep_ref_until_done.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+
+using webrtc::NativeHandleBuffer;
+
+namespace webrtc_jni {
+
+Matrix::Matrix(JNIEnv* jni, jfloatArray a) {
+  RTC_CHECK_EQ(16, jni->GetArrayLength(a));
+  jfloat* ptr = jni->GetFloatArrayElements(a, nullptr);
+  for (int i = 0; i < 16; ++i) {
+    elem_[i] = ptr[i];
+  }
+  jni->ReleaseFloatArrayElements(a, ptr, 0);
+}
+
+jfloatArray Matrix::ToJava(JNIEnv* jni) {
+  jfloatArray matrix = jni->NewFloatArray(16);
+  jni->SetFloatArrayRegion(matrix, 0, 16, elem_);
+  return matrix;
+}
+
+void Matrix::Rotate(webrtc::VideoRotation rotation) {
+  // Texture coordinates are in the range 0 to 1. The transformation of the last
+  // row in each rotation matrix is needed for proper translation, e.g, to
+  // mirror x, we don't replace x by -x, but by 1-x.
+  switch (rotation) {
+    case webrtc::kVideoRotation_0:
+      break;
+    case webrtc::kVideoRotation_90: {
+      const float ROTATE_90[16] =
+          { elem_[4], elem_[5], elem_[6], elem_[7],
+            -elem_[0], -elem_[1], -elem_[2], -elem_[3],
+            elem_[8], elem_[9], elem_[10], elem_[11],
+            elem_[0] + elem_[12], elem_[1] + elem_[13],
+            elem_[2] + elem_[14], elem_[3] + elem_[15]};
+      memcpy(elem_, ROTATE_90, sizeof(elem_));
+    } break;
+    case webrtc::kVideoRotation_180: {
+      const float ROTATE_180[16] =
+          { -elem_[0], -elem_[1], -elem_[2], -elem_[3],
+            -elem_[4], -elem_[5], -elem_[6], -elem_[7],
+            elem_[8], elem_[9], elem_[10], elem_[11],
+            elem_[0] + elem_[4] + elem_[12], elem_[1] + elem_[5] + elem_[13],
+            elem_[2] + elem_[6] + elem_[14], elem_[3] + elem_[11]+ elem_[15]};
+        memcpy(elem_, ROTATE_180, sizeof(elem_));
+    } break;
+    case webrtc::kVideoRotation_270: {
+      const float ROTATE_270[16] =
+          { -elem_[4], -elem_[5], -elem_[6], -elem_[7],
+            elem_[0], elem_[1], elem_[2], elem_[3],
+            elem_[8], elem_[9], elem_[10], elem_[11],
+            elem_[4] + elem_[12], elem_[5] + elem_[13],
+            elem_[6] + elem_[14], elem_[7] + elem_[15]};
+      memcpy(elem_, ROTATE_270, sizeof(elem_));
+    } break;
+  }
+}
+
+// Calculates result = a * b, in column-major order.
+void Matrix::Multiply(const float a[16], const float b[16], float result[16]) {
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 4; ++j) {
+      float sum = 0;
+      for (int k = 0; k < 4; ++k) {
+        sum += a[k * 4 + j] * b[i * 4 + k];
+      }
+      result[i * 4 + j] = sum;
+    }
+  }
+}
+
+// Center crop by keeping xFraction of the width and yFraction of the height,
+// so e.g. cropping from 640x480 to 640x360 would use
+// xFraction=1, yFraction=360/480.
+void Matrix::Crop(float xFraction,
+                  float yFraction,
+                  float xOffset,
+                  float yOffset) {
+  const float crop_matrix[16] =
+      {xFraction, 0, 0, 0,
+       0, yFraction, 0, 0,
+       0, 0, 1, 0,
+       xOffset, yOffset, 0, 1};
+  const Matrix old = *this;
+  Multiply(crop_matrix, old.elem_, this->elem_);
+}
+
+// Aligning pointer to 64 bytes for improved performance, e.g. use SIMD.
+static const int kBufferAlignment = 64;
+
+NativeHandleImpl::NativeHandleImpl(int id, const Matrix& matrix)
+    : oes_texture_id(id), sampling_matrix(matrix) {}
+
+NativeHandleImpl::NativeHandleImpl(JNIEnv* jni,
+                                   jint j_oes_texture_id,
+                                   jfloatArray j_transform_matrix)
+    : oes_texture_id(j_oes_texture_id),
+      sampling_matrix(jni, j_transform_matrix) {}
+
+AndroidTextureBuffer::AndroidTextureBuffer(
+    int width,
+    int height,
+    const NativeHandleImpl& native_handle,
+    jobject surface_texture_helper,
+    const rtc::Callback0<void>& no_longer_used)
+    : webrtc::NativeHandleBuffer(&native_handle_, width, height),
+      native_handle_(native_handle),
+      surface_texture_helper_(surface_texture_helper),
+      no_longer_used_cb_(no_longer_used) {}
+
+AndroidTextureBuffer::~AndroidTextureBuffer() {
+  no_longer_used_cb_();
+}
+
+rtc::scoped_refptr<webrtc::VideoFrameBuffer>
+AndroidTextureBuffer::NativeToI420Buffer() {
+  int uv_width = (width()+7) / 8;
+  int stride = 8 * uv_width;
+  int uv_height = (height()+1)/2;
+  size_t size = stride * (height() + uv_height);
+  // The data is owned by the frame, and the normal case is that the
+  // data is deleted by the frame's destructor callback.
+  //
+  // TODO(nisse): Use an I420BufferPool. We then need to extend that
+  // class, and I420Buffer, to support our memory layout.
+  std::unique_ptr<uint8_t, webrtc::AlignedFreeDeleter> yuv_data(
+      static_cast<uint8_t*>(webrtc::AlignedMalloc(size, kBufferAlignment)));
+  // See SurfaceTextureHelper.java for the required layout.
+  uint8_t* y_data = yuv_data.get();
+  uint8_t* u_data = y_data + height() * stride;
+  uint8_t* v_data = u_data + stride/2;
+
+  rtc::scoped_refptr<webrtc::VideoFrameBuffer> copy =
+    new rtc::RefCountedObject<webrtc::WrappedI420Buffer>(
+        width(), height(),
+        y_data, stride,
+        u_data, stride,
+        v_data, stride,
+        rtc::Bind(&webrtc::AlignedFree, yuv_data.release()));
+
+  JNIEnv* jni = AttachCurrentThreadIfNeeded();
+  ScopedLocalRefFrame local_ref_frame(jni);
+
+  jmethodID transform_mid = GetMethodID(
+      jni,
+      GetObjectClass(jni, surface_texture_helper_),
+      "textureToYUV",
+      "(Ljava/nio/ByteBuffer;IIII[F)V");
+
+  jobject byte_buffer = jni->NewDirectByteBuffer(y_data, size);
+
+  jfloatArray sampling_matrix = native_handle_.sampling_matrix.ToJava(jni);
+  jni->CallVoidMethod(surface_texture_helper_,
+                      transform_mid,
+                      byte_buffer, width(), height(), stride,
+                      native_handle_.oes_texture_id, sampling_matrix);
+  CHECK_EXCEPTION(jni) << "textureToYUV throwed an exception";
+
+  return copy;
+}
+
+rtc::scoped_refptr<AndroidTextureBuffer>
+AndroidTextureBuffer::CropScaleAndRotate(int cropped_width,
+                                         int cropped_height,
+                                         int crop_x,
+                                         int crop_y,
+                                         int dst_width,
+                                         int dst_height,
+                                         webrtc::VideoRotation rotation) {
+  if (cropped_width == dst_width && cropped_height == dst_height &&
+      width() == dst_width && height() == dst_height &&
+      rotation == webrtc::kVideoRotation_0) {
+    return this;
+  }
+  int rotated_width = (rotation % 180 == 0) ? dst_width : dst_height;
+  int rotated_height = (rotation % 180 == 0) ? dst_height : dst_width;
+
+  // Here we use Bind magic to add a reference count to |this| until the newly
+  // created AndroidTextureBuffer is destructed
+  rtc::scoped_refptr<AndroidTextureBuffer> buffer(
+      new rtc::RefCountedObject<AndroidTextureBuffer>(
+          rotated_width, rotated_height, native_handle_,
+          surface_texture_helper_, rtc::KeepRefUntilDone(this)));
+
+  if (cropped_width != width() || cropped_height != height()) {
+    buffer->native_handle_.sampling_matrix.Crop(
+        cropped_width / static_cast<float>(width()),
+        cropped_height / static_cast<float>(height()),
+        crop_x / static_cast<float>(width()),
+        crop_y / static_cast<float>(height()));
+  }
+  buffer->native_handle_.sampling_matrix.Rotate(rotation);
+  return buffer;
+}
+
+}  // namespace webrtc_jni