CL for perf tryjob on linux

cc/playback/display_item_list.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/display_item_list.h"
 
 #include <string>
 
 #include "base/numerics/safe_conversions.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 17 matching lines @@
 // operations.
 const int kOpCountThatIsOkToAnalyze = 10;
 
 bool DisplayItemsTracingEnabled() {
   bool tracing_enabled;
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(
       TRACE_DISABLED_BY_DEFAULT("cc.debug.display_items"), &tracing_enabled);
   return tracing_enabled;
 }
 
-const int kDefaultNumDisplayItemsToReserve = 100;
+// 16 "typically sized items" is the same as this many large items:
+const int kDefaultNumDisplayItemsToReserve =
+    8 * TypicalDisplayItemSize() / LargestDisplayItemSize() + 1;
 
 }  // namespace
 
 scoped_refptr<DisplayItemList> DisplayItemList::Create(
     const gfx::Rect& layer_rect,
     const DisplayItemListSettings& settings) {
   return make_scoped_refptr(new DisplayItemList(
       layer_rect, settings,
       !settings.use_cached_picture || DisplayItemsTracingEnabled()));
 }
@@ skipping 52 matching lines @@
       // entire picture on the canvas instead of parsing the skia operations.
       canvas->drawPicture(picture_.get());
     }
     canvas->restore();
   }
 }
 
 void DisplayItemList::ProcessAppendedItemsOnTheFly() {
   if (retain_individual_display_items_)
     return;
-  if (items_.size() >= kDefaultNumDisplayItemsToReserve) {
+  if (items_.size() >= static_cast<size_t>(kDefaultNumDisplayItemsToReserve)) {
     ProcessAppendedItems();
     // This function exists to keep the |items_| from growing indefinitely if
     // we're not going to store them anyway. So the items better be deleted
     // after |items_| grows too large and we process it.
     DCHECK(items_.empty());
   }
 }
 
 void DisplayItemList::ProcessAppendedItems() {
 #if DCHECK_IS_ON()
@@ skipping 164 matching lines @@
   generator.canvas()->drawPicture(picture_.get());
 }
 
 void DisplayItemList::GetDiscardableImagesInRect(
     const gfx::Rect& rect,
     std::vector<PositionImage>* images) {
   image_map_.GetDiscardableImagesInRect(rect, images);
 }
 
 }  // namespace cc