Limit memory usage for sqlite3 fuzzer + move it to sqlite dir.

third_party/sqlite/BUILD.gn

Index: third_party/sqlite/BUILD.gn
diff --git a/third_party/sqlite/BUILD.gn b/third_party/sqlite/BUILD.gn
index 2f668b834bababd395553f4751f8d9043c4b24d7..8d3f9deb1287f6010ff9223da5bd5c386bb3cd22 100644
--- a/third_party/sqlite/BUILD.gn
+++ b/third_party/sqlite/BUILD.gn
@@ -2,6 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//testing/libfuzzer/fuzzer_test.gni")
+
 declare_args() {
   # Controls whether the build should uses the version of sqlite3 library
   # shipped with the system (currently only supported on iOS) or the one
@@ -34,7 +36,6 @@ if (!use_system_sqlite) {
   # "sqlite3" can cause conflicts with the system library.
   component("chromium_sqlite3") {
     visibility = [ ":*" ]
-
     sources = [
       "amalgamation/config.h",
       "amalgamation/sqlite3.c",
@@ -129,6 +130,14 @@ if (!use_system_sqlite) {
       defines += [ "_HAVE_SQLITE_CONFIG_H" ]
     }
 
+    if (use_libfuzzer) {

[mmoroz, 2016/11/11 15:24:05]

That's wrong, we have another flag which should work for more cases (e.g.
use_afl). I'll update this line.

[Scott Hess - ex-Googler, 2016/11/11 15:43:09]

WRT my LGTM, consider it sticky WRT the other code, because I'm not in a
position to consider whether you're using the right gn flag :-).  But using that
to limit the lengths seems reasonable.

+      # Limit max length of data blobs and queries by 128M for fuzzing build.
+      defines += [
+        "SQLITE_MAX_LENGTH=128000000",
+        "SQLITE_MAX_SQL_LENGTH=128000000",
+      ]
+    }
+
     include_dirs = [ "amalgamation" ]
 
     configs -= [ "//build/config/compiler:chromium_code" ]
@@ -256,3 +265,13 @@ if (use_system_sqlite) {
     }
   }
 }
+
+fuzzer_test("sqlite3_prepare_v2_fuzzer") {
+  sources = [
+    "fuzz/sqlite3_prepare_v2_fuzzer.cc",
+  ]
+  deps = [
+    ":sqlite",
+  ]
+  dict = "//testing/libfuzzer/fuzzers/dicts/generated/sqlite3_prepare_v2_fuzzer.dict"
+}