Fix cursor missing in tabCapture on OSX Sierra

content/browser/media/capture/cursor_renderer.cc

Index: content/browser/media/capture/cursor_renderer.cc
diff --git a/content/browser/media/capture/cursor_renderer.cc b/content/browser/media/capture/cursor_renderer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c92645ff0d85b7b96de881c06461d6236e5ce8f3
--- /dev/null
+++ b/content/browser/media/capture/cursor_renderer.cc
@@ -0,0 +1,206 @@
+// Copyright (c) 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/media/capture/cursor_renderer.h"
+
+#include <algorithm>
+#include <cmath>
+
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "skia/ext/image_operations.h"
+
+namespace content {
+
+namespace {
+
+inline int clip_byte(int x) {
+  return std::max(0, std::min(x, 255));
+}
+
+inline int alpha_blend(int alpha, int src, int dst) {
+  return (src * alpha + dst * (255 - alpha)) / 255;
+}
+
+}  // namespace
+
+CursorRenderer::CursorRenderer(gfx::NativeView view,
+                               CursorDisplaySetting cursor_display_setting)
+    : captured_view_(view),
+      cursor_display_setting_(cursor_display_setting),
+      tick_clock_(&default_tick_clock_),
+      weak_factory_(this) {
+  Clear();
+}
+
+CursorRenderer::~CursorRenderer() {}
+
+base::WeakPtr<CursorRenderer> CursorRenderer::GetWeakPtr() {
+  return weak_factory_.GetWeakPtr();
+}
+
+void CursorRenderer::Clear() {
+  last_x_scale_ = 0.0f;
+  last_y_scale_ = 0.0f;
+  last_cursor_ = gfx::NativeCursor();
+  last_cursor_hot_point_ = gfx::Point();
+  scaled_cursor_bitmap_.reset();
+  last_mouse_position_x_ = 0;
+  last_mouse_position_y_ = 0;
+  last_mouse_movement_timestamp_ = base::TimeTicks::Now();
+  if (cursor_display_setting_ == kCursorEnabledOnMouseMovement) {
+    cursor_displayed_ = false;
+  } else {
+    cursor_displayed_ = true;
+  }
+}
+
+bool CursorRenderer::SnapshotCursorState(const gfx::Rect& region_in_frame) {
+  if (!captured_view_) {
+    DVLOG(2) << "Skipping update with no view being tracked";
+    return false;
+  }
+
+  // If we are sharing the root view, or namely the whole screen, we will
+  // render the mouse cursor. For ordinary view, we only render the mouse
+  // cursor when the view is active.
+  if (!IsCapturedViewActive()) {
+    // Return early if the target view is not active.
+    DVLOG(2) << "Skipping update on an inactive view";
+    Clear();
+    return false;
+  }
+
+  gfx::Size view_size = GetCapturedViewSize();
+  if (view_size.IsEmpty()) {
+    DVLOG(2) << "Skipping update on an empty view";
+    Clear();
+    return false;
+  }
+
+  gfx::Point cursor_position = GetCursorPositionInView();
+  if (!gfx::Rect(view_size).Contains(cursor_position)) {
+    DVLOG(2) << "Skipping update with cursor outside the view";
+    Clear();
+    return false;
+  }
+
+  if (cursor_display_setting_ == kCursorEnabledOnMouseMovement) {
+    if (cursor_displayed_) {
+      // Stop displaying cursor if there has been no mouse movement
+      base::TimeTicks now = tick_clock_->NowTicks();
+      if ((now - last_mouse_movement_timestamp_) >
+          base::TimeDelta::FromSeconds(MAX_IDLE_TIME_SECONDS)) {
+        cursor_displayed_ = false;
+        DVLOG(2) << "Turning off cursor display after idle time";
+      }
+    }
+    if (!cursor_displayed_)
+      return false;
+  }
+
+  const float x_scale =
+      static_cast<float>(region_in_frame.width()) / view_size.width();
+  const float y_scale =
+      static_cast<float>(region_in_frame.height()) / view_size.height();
+
+  gfx::NativeCursor cursor = GetLastKnownCursor();
+  if (last_cursor_ != cursor || last_x_scale_ != x_scale ||
+      last_y_scale_ != y_scale) {
+    SkBitmap cursor_bitmap = GetLastKnownCursorImage(&last_cursor_hot_point_);
+    const int scaled_width = cursor_bitmap.width() * x_scale;
+    const int scaled_height = cursor_bitmap.height() * y_scale;
+    if (scaled_width <= 0 || scaled_height <= 0) {
+      DVLOG(2) << "scaled_width <= 0";
+      Clear();
+      return false;
+    }
+    scaled_cursor_bitmap_ = skia::ImageOperations::Resize(
+        cursor_bitmap, skia::ImageOperations::RESIZE_BEST, scaled_width,
+        scaled_height);
+
+    last_cursor_ = cursor;
+    last_x_scale_ = x_scale;
+    last_y_scale_ = y_scale;
+  }
+
+  cursor_position.Offset(-last_cursor_hot_point_.x(),
+                         -last_cursor_hot_point_.y());
+  cursor_position_in_frame_ =
+      gfx::Point(region_in_frame.x() + cursor_position.x() * x_scale,
+                 region_in_frame.y() + cursor_position.y() * y_scale);
+  return true;
+}
+
+// Helper function to composite a cursor bitmap on a YUV420 video frame.
+void CursorRenderer::RenderOnVideoFrame(media::VideoFrame* target) const {
+  if (scaled_cursor_bitmap_.isNull())
+    return;
+
+  DCHECK(target);
+
+  gfx::Rect rect = gfx::IntersectRects(
+      gfx::Rect(scaled_cursor_bitmap_.width(), scaled_cursor_bitmap_.height()) +
+          gfx::Vector2d(cursor_position_in_frame_.x(),
+                        cursor_position_in_frame_.y()),
+      target->visible_rect());
+
+  scaled_cursor_bitmap_.lockPixels();
+  for (int y = rect.y(); y < rect.bottom(); ++y) {
+    int cursor_y = y - cursor_position_in_frame_.y();
+    uint8_t* yplane = target->data(media::VideoFrame::kYPlane) +
+                      y * target->row_bytes(media::VideoFrame::kYPlane);
+    uint8_t* uplane = target->data(media::VideoFrame::kUPlane) +
+                      (y / 2) * target->row_bytes(media::VideoFrame::kUPlane);
+    uint8_t* vplane = target->data(media::VideoFrame::kVPlane) +
+                      (y / 2) * target->row_bytes(media::VideoFrame::kVPlane);
+    for (int x = rect.x(); x < rect.right(); ++x) {
+      int cursor_x = x - cursor_position_in_frame_.x();
+      SkColor color = scaled_cursor_bitmap_.getColor(cursor_x, cursor_y);
+      int alpha = SkColorGetA(color);
+      int color_r = SkColorGetR(color);
+      int color_g = SkColorGetG(color);
+      int color_b = SkColorGetB(color);
+      int color_y = clip_byte(
+          ((color_r * 66 + color_g * 129 + color_b * 25 + 128) >> 8) + 16);
+      yplane[x] = alpha_blend(alpha, color_y, yplane[x]);
+
+      // Only sample U and V at even coordinates.
+      if ((x % 2 == 0) && (y % 2 == 0)) {
+        int color_u = clip_byte(
+            ((color_r * -38 + color_g * -74 + color_b * 112 + 128) >> 8) + 128);
+        int color_v = clip_byte(
+            ((color_r * 112 + color_g * -94 + color_b * -18 + 128) >> 8) + 128);
+        uplane[x / 2] = alpha_blend(alpha, color_u, uplane[x / 2]);
+        vplane[x / 2] = alpha_blend(alpha, color_v, vplane[x / 2]);
+      }
+    }
+  }
+  scaled_cursor_bitmap_.unlockPixels();
+}
+
+void CursorRenderer::OnMouseMoved(const gfx::Point& location,
+                                  base::TimeTicks timestamp) {
+  if (!cursor_displayed_) {
+    if (std::abs(location.x() - last_mouse_position_x_) > MIN_MOVEMENT_PIXELS ||
+        std::abs(location.y() - last_mouse_position_y_) > MIN_MOVEMENT_PIXELS)
+      cursor_displayed_ = true;
+  }
+
+  if (cursor_displayed_) {
+    last_mouse_movement_timestamp_ = timestamp;
+    last_mouse_position_x_ = location.x();
+    last_mouse_position_y_ = location.y();
+  }
+}
+
+void CursorRenderer::OnMouseClicked(const gfx::Point& location,
+                                    base::TimeTicks timestamp) {
+  cursor_displayed_ = true;
+  last_mouse_movement_timestamp_ = timestamp;
+  last_mouse_position_x_ = location.x();
+  last_mouse_position_y_ = location.y();
+}
+
+}  // namespace content