Revert of Adding total available size of heap in v8 isolate memory dump provider.

gin/v8_isolate_memory_dump_provider.cc

 // Copyright 2015 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 "gin/v8_isolate_memory_dump_provider.h"
 
 #include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/trace_event/memory_dump_manager.h"
@@ skipping 35 matching lines @@
   return true;
 }
 
 void V8IsolateMemoryDumpProvider::DumpMemoryStatistics(
     base::trace_event::ProcessMemoryDump* pmd) {
   v8::HeapStatistics heap_statistics;
   isolate_holder_->isolate()->GetHeapStatistics(&heap_statistics);
 
   size_t known_spaces_used_size = 0;
   size_t known_spaces_size = 0;
-  size_t known_spaces_available_size = 0;
   size_t number_of_spaces = isolate_holder_->isolate()->NumberOfHeapSpaces();
   for (size_t space = 0; space < number_of_spaces; space++) {
     v8::HeapSpaceStatistics space_statistics;
     isolate_holder_->isolate()->GetHeapSpaceStatistics(&space_statistics,
                                                        space);
     const size_t space_size = space_statistics.space_size();
     const size_t space_used_size = space_statistics.space_used_size();
-    size_t space_available_size = space_statistics.space_available_size();
 
     known_spaces_size += space_size;
     known_spaces_used_size += space_used_size;
-    known_spaces_available_size += space_available_size;
 
     std::string allocator_name =
         base::StringPrintf("%s/%s_%p/%s/%s", kRootDumpName, kIsolateDumpName,
                            isolate_holder_->isolate(), kHeapSpacesDumpName,
                            space_statistics.space_name());
     base::trace_event::MemoryAllocatorDump* space_dump =
         pmd->CreateAllocatorDump(allocator_name);
     space_dump->AddScalar(
         base::trace_event::MemoryAllocatorDump::kNameOuterSize,
         base::trace_event::MemoryAllocatorDump::kUnitsBytes, space_size);
 
+    // TODO(ssid): Fix crbug.com/481504 to get the objects count of live objects
+    // after the last GC.
     space_dump->AddScalar(
         base::trace_event::MemoryAllocatorDump::kNameInnerSize,
         base::trace_event::MemoryAllocatorDump::kUnitsBytes, space_used_size);
     space_dump->AddScalar(kAvailableSizeAttribute,
                           base::trace_event::MemoryAllocatorDump::kUnitsBytes,
-                          space_available_size);
+                          space_statistics.space_available_size());
   }
   // Compute the rest of the memory, not accounted by the spaces above.
   std::string allocator_name = base::StringPrintf(
       "%s/%s_%p/%s/%s", kRootDumpName, kIsolateDumpName,
       isolate_holder_->isolate(), kHeapSpacesDumpName, "other_spaces");
   base::trace_event::MemoryAllocatorDump* other_spaces_dump =
       pmd->CreateAllocatorDump(allocator_name);
   other_spaces_dump->AddScalar(
       base::trace_event::MemoryAllocatorDump::kNameOuterSize,
       base::trace_event::MemoryAllocatorDump::kUnitsBytes,
       heap_statistics.total_heap_size() - known_spaces_size);
   other_spaces_dump->AddScalar(
       base::trace_event::MemoryAllocatorDump::kNameInnerSize,
       base::trace_event::MemoryAllocatorDump::kUnitsBytes,
       heap_statistics.used_heap_size() - known_spaces_used_size);
 
   // TODO(ssid): Fix crbug.com/481504 to get the total available size of the
   // heap.
   other_spaces_dump->AddScalar(
       kAvailableSizeAttribute,
-      base::trace_event::MemoryAllocatorDump::kUnitsBytes,
-      heap_statistics.total_available_size() - known_spaces_available_size);
+      base::trace_event::MemoryAllocatorDump::kUnitsBytes, 0);
 }
 
 }  // namespace gin