Delay activation/draw on GPU tile work completion

cc/tiles/tile_draw_info.cc

 // Copyright 2013 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/tiles/tile_draw_info.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "cc/base/math_util.h"
 
 namespace cc {
 
 TileDrawInfo::TileDrawInfo()
-    : mode_(RESOURCE_MODE),
-      solid_color_(SK_ColorWHITE),
-      resource_(nullptr),
-      contents_swizzled_(false),
-      was_ever_ready_to_draw_(false),
+    : was_ever_ready_to_draw_(false),
       was_ever_used_to_draw_(false),
       was_a_prepaint_tile_(false) {}
 
 TileDrawInfo::~TileDrawInfo() {
   DCHECK(!resource_);
   if (was_ever_ready_to_draw_ && was_a_prepaint_tile_) {
     UMA_HISTOGRAM_BOOLEAN("Renderer4.ReadyToDrawTileDrawStatus",
                           was_ever_used_to_draw_);
   }
 }
 
 void TileDrawInfo::AsValueInto(base::trace_event::TracedValue* state) const {
   state->SetBoolean("is_solid_color", mode_ == SOLID_COLOR_MODE);
   state->SetBoolean("is_transparent",
                     mode_ == SOLID_COLOR_MODE && !SkColorGetA(solid_color_));
 }
 
 }  // namespace cc