Extract subpixel offsets from composited layer transforms when possible.

cc/playback/raster_source.cc

 // Copyright 2014 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 "cc/playback/raster_source.h"
 
 #include <stddef.h>
 
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
@@ skipping 51 matching lines @@
       can_use_lcd_text_(can_use_lcd_text),
       is_solid_color_(other->is_solid_color_),
       solid_color_(other->solid_color_),
       recorded_viewport_(other->recorded_viewport_),
       size_(other->size_),
       clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_),
       slow_down_raster_scale_factor_for_debug_(
           other->slow_down_raster_scale_factor_for_debug_),
       should_attempt_to_use_distance_field_text_(
           other->should_attempt_to_use_distance_field_text_),
-      image_decode_controller_(other->image_decode_controller_) {
+      image_decode_controller_(other->image_decode_controller_),
+      subpixel_offset_(other->subpixel_offset_) {
   // In certain cases, ThreadTaskRunnerHandle isn't set (Android Webview).
   // Don't register a dump provider in these cases.
   // TODO(ericrk): Get this working in Android Webview. crbug.com/517156
   if (base::ThreadTaskRunnerHandle::IsSet()) {
     base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
         this, "cc::RasterSource", base::ThreadTaskRunnerHandle::Get());
   }
 }
 
 RasterSource::~RasterSource() {
@@ skipping 144 matching lines @@
     }
   }
 }
 
 void RasterSource::RasterCommon(SkCanvas* canvas,
                                 SkPicture::AbortCallback* callback,
                                 const gfx::Rect& canvas_bitmap_rect,
                                 const gfx::Rect& canvas_playback_rect,
                                 float contents_scale) const {
   canvas->translate(-canvas_bitmap_rect.x(), -canvas_bitmap_rect.y());
+  LOG(ERROR) << "subpixel_offset: " << this << ": " << subpixel_offset_.ToString() << ": " << GetSize().ToString();
+  canvas->translate(subpixel_offset_.x(), subpixel_offset_.y());
   gfx::Rect content_rect =
       gfx::ScaleToEnclosingRect(gfx::Rect(size_), contents_scale);
   content_rect.Intersect(canvas_playback_rect);
 
   canvas->clipRect(gfx::RectToSkRect(content_rect), SkRegion::kIntersect_Op);
 
   DCHECK(display_list_.get());
   gfx::Rect canvas_target_playback_rect =
       canvas_playback_rect - canvas_bitmap_rect.OffsetFromOrigin();
   int repeat_count = std::max(1, slow_down_raster_scale_factor_for_debug_);
@@ skipping 121 matching lines @@
     base::trace_event::MemoryAllocatorDump* dump =
         pmd->CreateAllocatorDump(dump_name);
     dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
                     base::trace_event::MemoryAllocatorDump::kUnitsBytes,
                     memory_usage);
   }
   return true;
 }
 
 }  // namespace cc