cc: Clean up naming of paint-related identifiers

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1043 matching lines @@
   viewport_damage_rect_.Union(damage_rect);
 }
 
 DrawResult LayerTreeHostImpl::PrepareToDraw(FrameData* frame) {
   TRACE_EVENT1("cc", "LayerTreeHostImpl::PrepareToDraw", "SourceFrameNumber",
                active_tree_->source_frame_number());
   if (input_handler_client_)
     input_handler_client_->ReconcileElasticOverscrollAndRootScroll();
 
   if (const char* client_name = GetClientNameForMetrics()) {
-    size_t total_picture_memory = 0;
+    size_t total_memory = 0;
     for (const PictureLayerImpl* layer : active_tree()->picture_layers())
-      total_picture_memory += layer->GetRasterSource()->GetPictureMemoryUsage();
-    if (total_picture_memory != 0) {
+      total_memory += layer->GetRasterSource()->GetMemoryUsage();
+    if (total_memory != 0) {
       // GetClientNameForMetrics only returns one non-null value over the
       // lifetime of the process, so this histogram name is runtime constant.
       UMA_HISTOGRAM_COUNTS(
           base::StringPrintf("Compositing.%s.PictureMemoryUsageKb",
                              client_name),
-          base::saturated_cast<int>(total_picture_memory / 1024));
+          base::saturated_cast<int>(total_memory / 1024));
     }
     // GetClientNameForMetrics only returns one non-null value over the lifetime
     // of the process, so this histogram name is runtime constant.
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         base::StringPrintf("Compositing.%s.NumActiveLayers", client_name),
         base::saturated_cast<int>(active_tree_->NumLayers()), 1, 400, 20);
   }
 
   bool update_lcd_text = false;
   bool ok = active_tree_->UpdateDrawProperties(update_lcd_text);
@@ skipping 3001 matching lines @@
       worker_context_visibility_ =
           worker_context->CacheController()->ClientBecameVisible();
     } else {
       worker_context->CacheController()->ClientBecameNotVisible(
           std::move(worker_context_visibility_));
     }
   }
 }
 
 }  // namespace cc