[tracing] Optimize TracedValue::AppendAsTraceFormat().

components/tracing/common/graphics_memory_dump_provider_android_unittest.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 "base/trace_event/memory_allocator_dump.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "components/tracing/common/graphics_memory_dump_provider_android.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace tracing {
 
 TEST(GraphicsMemoryDumpProviderTest, ParseResponse) {
   const char* kDumpBaseName = GraphicsMemoryDumpProvider::kDumpBaseName;
 
   base::trace_event::ProcessMemoryDump pmd(
       nullptr, {base::trace_event::MemoryDumpLevelOfDetail::DETAILED});
   auto* instance = GraphicsMemoryDumpProvider::GetInstance();
   char buf[] = "graphics_total 12\ngraphics_pss 34\ngl_total 56\ngl_pss 78";
   instance->ParseResponseAndAddToDump(buf, strlen(buf), &pmd);
 
   // Check the "graphics" row.
   auto* mad = pmd.GetAllocatorDump(kDumpBaseName + std::string("graphics"));
   ASSERT_TRUE(mad);
   std::string json;
   mad->attributes_for_testing()->AppendAsTraceFormat(&json);
   ASSERT_EQ(
-      "{\"memtrack_pss\":{\"type\":\"scalar\",\"units\":\"bytes\",\"value\":"
-      "\"22\"},"
-      "\"memtrack_total\":{\"type\":\"scalar\",\"units\":\"bytes\",\"value\":"
-      "\"c\"}}",
+      "{\"memtrack_total\":{\"type\":\"scalar\",\"units\":\"bytes\",\"value\":"
+      "\"c\"},"
+      "\"memtrack_pss\":{\"type\":\"scalar\",\"units\":\"bytes\",\"value\":"
+      "\"22\"}}",
       json);
 
   // Check the "gl" row.
   mad = pmd.GetAllocatorDump(kDumpBaseName + std::string("gl"));
   ASSERT_TRUE(mad);
   json = "";
   mad->attributes_for_testing()->AppendAsTraceFormat(&json);
   ASSERT_EQ(
-      "{\"memtrack_pss\":{\"type\":\"scalar\",\"units\":\"bytes\",\"value\":"
-      "\"4e\"},"
-      "\"memtrack_total\":{\"type\":\"scalar\",\"units\":\"bytes\",\"value\":"
-      "\"38\"}}",
+      "{\"memtrack_total\":{\"type\":\"scalar\",\"units\":\"bytes\",\"value\":"
+      "\"38\"},"
+      "\"memtrack_pss\":{\"type\":\"scalar\",\"units\":\"bytes\",\"value\":"
+      "\"4e\"}}",
       json);
 
   // Test for truncated input.
   pmd.Clear();
   instance->ParseResponseAndAddToDump(buf, strlen(buf) - 14, &pmd);
   ASSERT_TRUE(pmd.GetAllocatorDump(kDumpBaseName + std::string("graphics")));
   ASSERT_FALSE(pmd.GetAllocatorDump(kDumpBaseName + std::string("gl")));
 }
 
 }  // namespace tracing