cc: Add color space to image decode caches

cc/raster/raster_source.cc

Index: cc/raster/raster_source.cc
diff --git a/cc/raster/raster_source.cc b/cc/raster/raster_source.cc
index 43d7792336be2b6c7da6bb0f1ec0e3943f3d295c..b1fdb48d16cf3c4ced98708ab69e97e32a18df0f 100644
--- a/cc/raster/raster_source.cc
+++ b/cc/raster/raster_source.cc
@@ -61,7 +61,7 @@ RasterSource::RasterSource(const RasterSource* other, bool can_use_lcd_text)
 RasterSource::~RasterSource() {}
 
 void RasterSource::PlaybackToCanvas(SkCanvas* raster_canvas,
-                                    const gfx::ColorSpace& canvas_color_space,
+                                    const gfx::ColorSpace& target_color_space,
                                     const gfx::Rect& canvas_bitmap_rect,
                                     const gfx::Rect& canvas_playback_rect,
                                     float raster_scale,
@@ -77,23 +77,31 @@ void RasterSource::PlaybackToCanvas(SkCanvas* raster_canvas,
   raster_canvas->translate(-canvas_bitmap_rect.x(), -canvas_bitmap_rect.y());
   raster_canvas->clipRect(SkRect::MakeFromIRect(raster_bounds));
   raster_canvas->scale(raster_scale, raster_scale);
-  PlaybackToCanvas(raster_canvas, canvas_color_space, settings);
+  PlaybackToCanvas(raster_canvas, target_color_space, settings);
   raster_canvas->restore();
 }
 
-void RasterSource::PlaybackToCanvas(SkCanvas* raster_canvas,
-                                    const gfx::ColorSpace& canvas_color_space,
+void RasterSource::PlaybackToCanvas(SkCanvas* input_canvas,
+                                    const gfx::ColorSpace& target_color_space,
                                     const PlaybackSettings& settings) const {
+  SkCanvas* raster_canvas = input_canvas;
+  std::unique_ptr<SkCanvas> color_transform_canvas;
+  if (target_color_space.IsValid()) {
+    color_transform_canvas = SkCreateColorSpaceXformCanvas(
+        input_canvas, target_color_space.ToSkColorSpace());
+    raster_canvas = color_transform_canvas.get();
+  }
+
   if (!settings.playback_to_shared_canvas)
     PrepareForPlaybackToCanvas(raster_canvas);
 
   if (settings.skip_images) {
     SkipImageCanvas canvas(raster_canvas);
-    RasterCommon(&canvas, canvas_color_space, nullptr);
+    RasterCommon(&canvas, nullptr);
   } else if (settings.use_image_hijack_canvas) {
     const SkImageInfo& info = raster_canvas->imageInfo();
     ImageHijackCanvas canvas(info.width(), info.height(), image_decode_cache_,
-                             &settings.images_to_skip);
+                             &settings.images_to_skip, target_color_space);

[vmpstr, 2017/04/04 01:16:43]

ImageHijackCanvas intercepts some calls to things like drawImage, grabs the
needed image out of the cache, and then passes that to the underlying canvas'
drawImage. I assume that works correctly here? That is, we would be passing a
color converted image to the canvas created on line 90. Are SkImages already
tagged with the right color space at that point?

(I'm trying to avoid double conversion)

[ccameron, 2017/04/04 06:41:10]

Yeah, the input SkImage will be in "image color space" (usually sRGB, but could
be anything, in principle), and then the ImageHijackCanvas will replace it with
an SkImage that is in target_color_space. The SkColorSpaceXformCanvas will see
"oh, this image is already in my target_color_space, I don't need to do anything
here".

     // Before adding the canvas, make sure that the ImageHijackCanvas is aware
     // of the current transform and clip, which may affect the clip bounds.
     // Since we query the clip bounds of the current canvas to get the list of
@@ -103,9 +111,9 @@ void RasterSource::PlaybackToCanvas(SkCanvas* raster_canvas,
     canvas.setMatrix(raster_canvas->getTotalMatrix());
     canvas.addCanvas(raster_canvas);
 
-    RasterCommon(&canvas, canvas_color_space, nullptr);
+    RasterCommon(&canvas, nullptr);
   } else {
-    RasterCommon(raster_canvas, canvas_color_space, nullptr);
+    RasterCommon(raster_canvas, nullptr);
   }
 }
 
@@ -198,16 +206,8 @@ void RasterSource::PrepareForPlaybackToCanvas(SkCanvas* canvas) const {
   canvas->restore();
 }
 
-void RasterSource::RasterCommon(SkCanvas* input_canvas,
-                                const gfx::ColorSpace& target_color_space,
+void RasterSource::RasterCommon(SkCanvas* raster_canvas,
                                 SkPicture::AbortCallback* callback) const {
-  SkCanvas* raster_canvas = input_canvas;
-  std::unique_ptr<SkCanvas> color_transform_canvas;
-  if (target_color_space.IsValid()) {
-    color_transform_canvas = SkCreateColorSpaceXformCanvas(
-        input_canvas, target_color_space.ToSkColorSpace());
-    raster_canvas = color_transform_canvas.get();
-  }
   DCHECK(display_list_.get());
   int repeat_count = std::max(1, slow_down_raster_scale_factor_for_debug_);
   for (int i = 0; i < repeat_count; ++i)
@@ -221,8 +221,7 @@ sk_sp<SkPicture> RasterSource::GetFlattenedPicture() {
   SkCanvas* canvas = recorder.beginRecording(size_.width(), size_.height());
   if (!size_.IsEmpty()) {
     PrepareForPlaybackToCanvas(canvas);
-    // No target color space should be set for generating an SkPicture.
-    RasterCommon(canvas, gfx::ColorSpace(), nullptr);
+    RasterCommon(canvas, nullptr);
   }
 
   return recorder.finishRecordingAsPicture();
@@ -246,18 +245,20 @@ bool RasterSource::PerformSolidColorAnalysis(const gfx::Rect& content_rect,
   layer_rect.Intersect(gfx::Rect(size_));
   skia::AnalysisCanvas canvas(layer_rect.width(), layer_rect.height());
   canvas.translate(-layer_rect.x(), -layer_rect.y());
-  // No target color space should be set for solid color analysis (the
-  // resulting solid color will be known to be sRGB).
-  RasterCommon(&canvas, gfx::ColorSpace(), &canvas);
+  // Note that because no color conversion is applied to solid color analysis,
+  // the resulting solid color will be known to be sRGB.
+  RasterCommon(&canvas, &canvas);
   return canvas.GetColorIfSolid(color);
 }
 
 void RasterSource::GetDiscardableImagesInRect(
     const gfx::Rect& layer_rect,
     float contents_scale,
+    const gfx::ColorSpace& target_color_space,
     std::vector<DrawImage>* images) const {
   DCHECK_EQ(0u, images->size());
-  display_list_->GetDiscardableImagesInRect(layer_rect, contents_scale, images);
+  display_list_->GetDiscardableImagesInRect(layer_rect, contents_scale,
+                                            target_color_space, images);
 }
 
 gfx::Rect RasterSource::GetRectForImage(ImageId image_id) const {