Change memory dumps to not use periodic dumps by default.

All consumers that require periodic dumps now explicitly specify a dump config.
Remove by default the periodic dump config.

BUG=726393

Review-Url: https://codereview.chromium.org/2952083004
Cr-Commit-Position: refs/heads/master@{#481951}

base/trace_event/memory_dump_manager_unittest.cc

@@ -891,17 +891,17 @@ TEST_F(MemoryDumpManagerTest, TraceConfigExpectationsWhenIsCoordinator) {
   InitializeMemoryDumpManagerForInProcessTesting(true /* is_coordinator */);
 
   // Enabling memory-infra with the legacy TraceConfig (category filter) in
-  // a coordinator process should enable periodic dumps.
+  // a coordinator process should not enable periodic dumps.
   EnableTracingWithLegacyCategories(MemoryDumpManager::kTraceCategory);
-  EXPECT_TRUE(IsPeriodicDumpingEnabled());
+  EXPECT_FALSE(IsPeriodicDumpingEnabled());
   DisableTracing();
 
   // Enabling memory-infra with the new (JSON) TraceConfig in a coordinator
-  // process without specifying any "memory_dump_config" section should enable
+  // process while specifying a "memory_dump_config" section should enable
   // periodic dumps. This is to preserve the behavior chrome://tracing UI, that
-  // is: ticking memory-infra should dump periodically with the default config.
+  // is: ticking memory-infra should dump periodically with an explicit config.
   EnableTracingWithTraceConfig(
-      TraceConfigMemoryTestUtil::GetTraceConfig_NoTriggers());
+      TraceConfigMemoryTestUtil::GetTraceConfig_PeriodicTriggers(100, 5));
   EXPECT_TRUE(IsPeriodicDumpingEnabled());
   DisableTracing();
 

base/trace_event/trace_config.cc

@@ -51,11 +51,6 @@ const char kEventFiltersParam[] = "event_filters";
 const char kFilterPredicateParam[] = "filter_predicate";
 const char kFilterArgsParam[] = "filter_args";
 
-// Default configuration of memory dumps.
-const TraceConfig::MemoryDumpConfig::Trigger kDefaultMemoryDumpTrigger = {
-    5000,  // min_time_between_dumps_ms
-    MemoryDumpLevelOfDetail::DETAILED, MemoryDumpType::PERIODIC_INTERVAL};
-
 class ConvertableTraceConfigToTraceFormat
     : public base::trace_event::ConvertableToTraceFormat {
  public:
@@ -459,7 +454,6 @@ void TraceConfig::SetMemoryDumpConfigFromConfigDict(
 
 void TraceConfig::SetDefaultMemoryDumpConfig() {
   memory_dump_config_.Clear();
-  memory_dump_config_.triggers.push_back(kDefaultMemoryDumpTrigger);
   memory_dump_config_.allowed_dump_modes = GetDefaultAllowedMemoryDumpModes();
 }
 

base/trace_event/trace_config_unittest.cc

@@ -697,7 +697,7 @@ TEST(TraceConfigTest, LegacyStringToMemoryDumpConfig) {
   TraceConfig tc(MemoryDumpManager::kTraceCategory, "");
   EXPECT_TRUE(tc.IsCategoryGroupEnabled(MemoryDumpManager::kTraceCategory));
   EXPECT_NE(std::string::npos, tc.ToString().find("memory_dump_config"));
-  EXPECT_EQ(1u, tc.memory_dump_config().triggers.size());
+  EXPECT_EQ(0u, tc.memory_dump_config().triggers.size());
   EXPECT_EQ(
       TraceConfig::MemoryDumpConfig::HeapProfiler ::
           kDefaultBreakdownThresholdBytes,