Mac: Add detection for low power video compatible frames

ui/accelerated_widget_mac/ca_renderer_layer_tree.mm

 // Copyright 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 "ui/accelerated_widget_mac/ca_renderer_layer_tree.h"
 
 #include <AVFoundation/AVFoundation.h>
 #include <CoreMedia/CoreMedia.h>
 #include <CoreVideo/CoreVideo.h>
 #include <GLES2/gl2extchromium.h>
@@ skipping 156 matching lines @@
   }
 
   root_layer_.CommitToCA(superlayer, old_root_layer, scale_factor);
   // If there are any extra CALayers in |old_tree| that were not stolen by this
   // tree, they will be removed from the CALayer tree in this deallocation.
   old_tree.reset();
   has_committed_ = true;
   scale_factor_ = scale_factor;
 }
 
+bool CARendererLayerTree::CommitFullscreenLowPowerLayer(
+    AVSampleBufferDisplayLayer* fullscreen_low_power_layer) {
+  DCHECK(has_committed_);
+  ContentLayer* video_layer = nullptr;
+  gfx::RectF video_layer_frame_dip;
+  for (auto& clip_layer : root_layer_.clip_and_sorting_layers) {

[erikchen, 2016/04/26 23:56:21]

const auto& for all loops

[ccameron, 2016/04/27 20:01:10]

Done.

+    for (auto& transform_layer : clip_layer.transform_layers) {
+      for (auto& content_layer : transform_layer.content_layers) {
+        // Detached mode requires that no layers be on top of the video layer.
+        if (video_layer)
+          return false;
+
+        // See if this is the video layer.
+        if (content_layer.use_av_layer) {
+          video_layer = &content_layer;
+          video_layer_frame_dip = gfx::RectF(video_layer->rect);
+          if (!transform_layer.transform.IsPositiveScaleOrTranslation())
+            return false;
+          if (content_layer.opacity != 1)
+            return false;
+          transform_layer.transform.TransformRect(&video_layer_frame_dip);
+          video_layer_frame_dip.Scale(1 / scale_factor_);
+          continue;
+        }
+
+        // If we haven't found the video layer yet, make sure everything is
+        // solid black or transparent
+        if (content_layer.io_surface)
+          return false;
+        if (content_layer.background_color != SK_ColorBLACK &&
+            content_layer.background_color != SK_ColorTRANSPARENT) {
+          return false;
+        }
+      }
+    }
+  }
+  if (!video_layer)
+    return false;
+
+  if (video_layer->cv_pixel_buffer) {
+    AVSampleBufferDisplayLayerEnqueueCVPixelBuffer(
+        fullscreen_low_power_layer, video_layer->cv_pixel_buffer);
+  } else {
+    AVSampleBufferDisplayLayerEnqueueIOSurface(fullscreen_low_power_layer,
+                                               video_layer->io_surface);
+  }
+  [fullscreen_low_power_layer setVideoGravity:AVLayerVideoGravityResize];
+  [fullscreen_low_power_layer setFrame:video_layer_frame_dip.ToCGRect()];
+  return true;
+}
+
+
 CARendererLayerTree::RootLayer::RootLayer() {}
 
 // Note that for all destructors, the the CALayer will have been reset to nil if
 // another layer has taken it.
 CARendererLayerTree::RootLayer::~RootLayer() {
   [ca_layer removeFromSuperlayer];
 }
 
 CARendererLayerTree::ClipAndSortingLayer::ClipAndSortingLayer(
     bool is_clipped,
@@ skipping 403 matching lines @@
     } else {
       // Grey represents a CALayer that has not changed.
       color.reset(CGColorCreateGenericRGB(0, 0, 0, 0.1));
     }
     [ca_layer setBorderWidth:1];
     [ca_layer setBorderColor:color];
   }
 }
 
 }  // namespace ui