[jumbo] rename variables name for jumbo build.

a patch[1] which is to fix jumbo build error was merged.
but g_instance_for_testing still keep in memory_dump_manager.cc.
that variable name looks like generic name which is some potential
to make same issue.
so it should be rename in order to void the same problem.

[1]https://chromium-review.googlesource.com/938821

Bug: 775547
Change-Id: Id7f3fc30a8118fb6f24f0e920ab530f44a27fa82
Reviewed-on: https://chromium-review.googlesource.com/938803Reviewed-by: Primiano Tucci <primiano@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539480}

base/trace_event/memory_dump_manager.cc

@@ -50,7 +50,7 @@ namespace {
 const char* const kTraceEventArgNames[] = {"dumps"};
 const unsigned char kTraceEventArgTypes[] = {TRACE_VALUE_TYPE_CONVERTABLE};
 
-MemoryDumpManager* g_instance_for_testing = nullptr;
+MemoryDumpManager* g_memory_dump_manager_for_testing = nullptr;
 
 // Temporary (until peak detector and scheduler are moved outside of here)
 // trampoline function to match the |request_dump_function| passed to Initialize
@@ -162,8 +162,8 @@ const char* const MemoryDumpManager::kSystemAllocatorPoolName =
 
 // static
 MemoryDumpManager* MemoryDumpManager::GetInstance() {
-  if (g_instance_for_testing)
-    return g_instance_for_testing;
+  if (g_memory_dump_manager_for_testing)
+    return g_memory_dump_manager_for_testing;
 
   return Singleton<MemoryDumpManager,
                    LeakySingletonTraits<MemoryDumpManager>>::get();
@@ -172,9 +172,9 @@ MemoryDumpManager* MemoryDumpManager::GetInstance() {
 // static
 std::unique_ptr<MemoryDumpManager>
 MemoryDumpManager::CreateInstanceForTesting() {
-  DCHECK(!g_instance_for_testing);
+  DCHECK(!g_memory_dump_manager_for_testing);
   std::unique_ptr<MemoryDumpManager> instance(new MemoryDumpManager());
-  g_instance_for_testing = instance.get();
+  g_memory_dump_manager_for_testing = instance.get();
   return instance;
 }
 
@@ -197,7 +197,7 @@ MemoryDumpManager::~MemoryDumpManager() {
   }
   AutoLock lock(lock_);
   dump_thread_.reset();
-  g_instance_for_testing = nullptr;
+  g_memory_dump_manager_for_testing = nullptr;
 }
 
 // static

base/trace_event/trace_log.cc

@@ -74,7 +74,7 @@ const size_t kEchoToConsoleTraceEventBufferChunks = 256;
 const size_t kTraceEventBufferSizeInBytes = 100 * 1024;
 const int kThreadFlushTimeoutMs = 3000;
 
-TraceLog* g_instance_for_trace_log_testing = nullptr;
+TraceLog* g_trace_log_for_testing = nullptr;
 
 #define MAX_TRACE_EVENT_FILTERS 32
 
@@ -335,11 +335,11 @@ TraceLog* TraceLog::GetInstance() {
 
 // static
 void TraceLog::ResetForTesting() {
-  if (!g_instance_for_trace_log_testing)
+  if (!g_trace_log_for_testing)
     return;
   CategoryRegistry::ResetForTesting();
-  g_instance_for_trace_log_testing->~TraceLog();
-  new (g_instance_for_trace_log_testing) TraceLog;
+  g_trace_log_for_testing->~TraceLog();
+  new (g_trace_log_for_testing) TraceLog;
 }
 
 TraceLog::TraceLog()
@@ -376,7 +376,7 @@ TraceLog::TraceLog()
 
   MemoryDumpManager::GetInstance()->RegisterDumpProvider(this, "TraceLog",
                                                          nullptr);
-  g_instance_for_trace_log_testing = this;
+  g_trace_log_for_testing = this;
 }
 
 TraceLog::~TraceLog() = default;