Raster PictureLayerTiling with fractional translation

cc/raster/gpu_raster_buffer_provider.cc

Index: cc/raster/gpu_raster_buffer_provider.cc
diff --git a/cc/raster/gpu_raster_buffer_provider.cc b/cc/raster/gpu_raster_buffer_provider.cc
index f4eadee502105419071aa77d8fdf221b9cd64e9b..1d8291c55c06128e3fadb50d93c2bb8ee9b79f50 100644
--- a/cc/raster/gpu_raster_buffer_provider.cc
+++ b/cc/raster/gpu_raster_buffer_provider.cc
@@ -33,6 +33,7 @@ static sk_sp<SkPicture> PlaybackToPicture(
     const gfx::Rect& raster_full_rect,
     const gfx::Rect& raster_dirty_rect,
     float scale,
+    const gfx::Vector2dF& translation,
     const RasterSource::PlaybackSettings& playback_settings) {
   // GPU raster doesn't do low res tiles, so should always include images.
   DCHECK(!playback_settings.skip_images);
@@ -63,6 +64,10 @@ static sk_sp<SkPicture> PlaybackToPicture(
   sk_sp<SkCanvas> canvas = sk_ref_sp(
       recorder.beginRecording(resource_size.width(), resource_size.height()));
   canvas->save();
+  canvas->translate(-raster_full_rect.x(), -raster_full_rect.y());
+  canvas->clipRect(gfx::RectToSkRect(playback_rect));
+  canvas->translate(translation.x(), translation.y());
+  canvas->scale(scale, scale);
 
   // The GPU image decode controller assumes that Skia is done with an image
   // when playback is complete. However, in this case, where we play back to a
@@ -73,8 +78,7 @@ static sk_sp<SkPicture> PlaybackToPicture(
   // later picture rasterization.
   RasterSource::PlaybackSettings settings = playback_settings;
   settings.use_image_hijack_canvas = false;
-  raster_source->PlaybackToCanvas(canvas.get(), raster_full_rect, playback_rect,
-                                  scale, settings);
+  raster_source->PlaybackToCanvas(canvas.get(), settings);
   canvas->restore();
   return recorder.finishRecordingAsPicture();
 }
@@ -147,12 +151,13 @@ void GpuRasterBufferProvider::RasterBufferImpl::Playback(
     const gfx::Rect& raster_dirty_rect,
     uint64_t new_content_id,
     float scale,
+    const gfx::Vector2dF& translation,
     const RasterSource::PlaybackSettings& playback_settings) {
   TRACE_EVENT0("cc", "GpuRasterBuffer::Playback");
-  client_->PlaybackOnWorkerThread(&lock_, sync_token_,
-                                  resource_has_previous_content_, raster_source,
-                                  raster_full_rect, raster_dirty_rect,
-                                  new_content_id, scale, playback_settings);
+  client_->PlaybackOnWorkerThread(
+      &lock_, sync_token_, resource_has_previous_content_, raster_source,
+      raster_full_rect, raster_dirty_rect, new_content_id, scale, translation,
+      playback_settings);
 }
 
 GpuRasterBufferProvider::GpuRasterBufferProvider(
@@ -245,6 +250,7 @@ void GpuRasterBufferProvider::PlaybackOnWorkerThread(
     const gfx::Rect& raster_dirty_rect,
     uint64_t new_content_id,
     float scale,
+    const gfx::Vector2dF& translation,
     const RasterSource::PlaybackSettings& playback_settings) {
   ContextProvider::ScopedContextLock scoped_context(worker_context_provider_);
   gpu::gles2::GLES2Interface* gl = scoped_context.ContextGL();
@@ -261,7 +267,8 @@ void GpuRasterBufferProvider::PlaybackOnWorkerThread(
 
   sk_sp<SkPicture> picture = PlaybackToPicture(
       raster_source, resource_has_previous_content, resource_lock->size(),
-      raster_full_rect, raster_dirty_rect, scale, playback_settings);
+      raster_full_rect, raster_dirty_rect, scale, translation,
+      playback_settings);
 
   // Turn on distance fields for layers that have ever animated.
   bool use_distance_field_text =