[sql] Enable HAVE_USLEEP for more platforms.

HAVE_USLEEP affects SQLite's sleep implementation, which is used when
SQLite waits for a lock to clear.  Browser databases are generally
uncontended, but this case could happen for WebDatabase in the renderer.

BUG=none

Review URL: https://codereview.chromium.org/827523004

Cr-Commit-Position: refs/heads/master@{#312460}

sql/sqlite_features_unittest.cc

@@ -112,4 +112,21 @@ TEST_F(SQLiteFeaturesTest, FTS3_Prefix) {
 }
 #endif
 
+#if !defined(USE_SYSTEM_SQLITE)
+// Verify that Chromium's SQLite is compiled with HAVE_USLEEP defined.  With
+// HAVE_USLEEP, SQLite uses usleep() with millisecond granularity.  Otherwise it
+// uses sleep() with second granularity.
+TEST_F(SQLiteFeaturesTest, UsesUsleep) {
+  base::TimeTicks before = base::TimeTicks::Now();
+  sqlite3_sleep(1);
+  base::TimeDelta delta = base::TimeTicks::Now() - before;
+
+  // It is not impossible for this to be over 1000 if things are compiled the
+  // right way.  But it is very unlikely, most platforms seem to be around
+  // <TBD>.
+  LOG(ERROR) << "Milliseconds: " << delta.InMilliseconds();
+  EXPECT_LT(delta.InMilliseconds(), 1000);
+}
+#endif
+
 }  // namespace

third_party/sqlite/BUILD.gn

@@ -45,6 +45,15 @@ source_set("sqlite") {
       "SQLITE_NO_SYNC",
     ]
   }
+  if (is_posix) {
+    defines += [
+      # Allow xSleep() call on Unix to use usleep() rather than sleep(), so it
+      # will have microsecond precision.  Should only affect contended databases
+      # via the busy callback.  Browser profile databases are mostly exclusive,
+      # but renderer databases may allow for contention.
+      "HAVE_USLEEP=1",
+    ]
+  }
 
   include_dirs = [
     "amalgamation",
@@ -69,7 +78,6 @@ source_set("sqlite") {
     libs = [ "CoreFoundation.framework" ]
   } else if (is_android) {
     defines += [
-      "HAVE_USLEEP=1",
       "SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT=1048576",
       "SQLITE_DEFAULT_AUTOVACUUM=1",
       "SQLITE_TEMP_STORE=3",

third_party/sqlite/sqlite.gyp

@@ -33,6 +33,16 @@
                 ],
           },
         ],
+        ['os_posix == 1', {
+          'defines': [
+            # Allow xSleep() call on Unix to use usleep() rather than sleep().
+            # Microsecond precision is better than second precision.  Should
+            # only affect contended databases via the busy callback.  Browser
+            # profile databases are mostly exclusive, but renderer databases may
+            # allow for contention.
+            'HAVE_USLEEP=1',
+          ],
+        }],
         ['use_system_sqlite', {
           'type': 'none',
           'direct_dependent_settings': {
@@ -132,7 +142,6 @@
             }],
             ['OS == "android"', {
               'defines': [
-                'HAVE_USLEEP=1',
                 'SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT=1048576',
                 'SQLITE_DEFAULT_AUTOVACUUM=1',
                 'SQLITE_TEMP_STORE=3',