[tracing] Add sqlite memory statistics to tracing.

The process-wide memory usage statistics of sqlite library is added to
chrome://tracing. The memory usage of sqlite library is mainly through
sqlite_malloc. The total usage of the process is recorded by
sqlite3_memory_used() api. This CL also adds per-connection memory
usage to tracing. Each connection uses memory for cache, schema and
statement, and these usages are recorded. sqlit3_malloc uses malloc
internally to allocate memory. So, thie memory is traced as
sub-allocation from system_allocator(malloc).
This CL lets us keep track of sqlite memory usage in chrome telemetry.

BUG=466141

Review URL: https://codereview.chromium.org/1327063002

Cr-Commit-Position: refs/heads/master@{#353549}

1 files changed, 9 insertions, 0 deletions

diff --git a/sql/connection_unittest.cc b/sql/connection_unittest.cc
index 0038a1d..d933a6d 100644
--- a/sql/connection_unittest.cc
+++ b/sql/connection_unittest.cc
@@ -11,6 +11,7 @@
 #include "base/metrics/statistics_recorder.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/histogram_tester.h"
+#include "base/trace_event/process_memory_dump.h"
 #include "sql/connection.h"
 #include "sql/correct_sql_test_base.h"
 #include "sql/meta_table.h"
@@ -1378,4 +1379,12 @@ TEST_F(SQLConnectionTest, MmapTest) {
 }
 #endif
 
+TEST_F(SQLConnectionTest, OnMemoryDump) {
+  base::trace_event::ProcessMemoryDump pmd(nullptr);
+  base::trace_event::MemoryDumpArgs args = {
+      base::trace_event::MemoryDumpLevelOfDetail::DETAILED};
+  ASSERT_TRUE(db().OnMemoryDump(args, &pmd));
+  EXPECT_GE(pmd.allocator_dumps().size(), 1u);
+}
+
 }  // namespace