Fix integration tests in src/chrome and src/extensions so that we can turn on IO thread checks wi...

chrome/test/ppapi/ppapi_filechooser_browsertest.cc

Index: chrome/test/ppapi/ppapi_filechooser_browsertest.cc
diff --git a/chrome/test/ppapi/ppapi_filechooser_browsertest.cc b/chrome/test/ppapi/ppapi_filechooser_browsertest.cc
index ae3c0a628049c50c0f5d320e35a2510cc1b8f0c7..897e15b47c6dbdc6c4fcd2f153885e30021e6850 100644
--- a/chrome/test/ppapi/ppapi_filechooser_browsertest.cc
+++ b/chrome/test/ppapi/ppapi_filechooser_browsertest.cc
@@ -11,6 +11,7 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/ppapi/ppapi_test.h"
@@ -270,6 +271,7 @@ class PPAPIFileChooserTestWithSBService : public PPAPIFileChooserTest {
 
 IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest, FileChooser_Open_Success) {
   const char kContents[] = "Hello from browser";
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   base::ScopedTempDir temp_dir;
   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
 
@@ -294,6 +296,7 @@ IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest, FileChooser_Open_Cancel) {
 }
 
 IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest, FileChooser_SaveAs_Success) {
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   base::ScopedTempDir temp_dir;
   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
   base::FilePath suggested_filename = temp_dir.GetPath().AppendASCII("foo");
@@ -310,6 +313,7 @@ IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest, FileChooser_SaveAs_Success) {
 
 IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest,
                        FileChooser_SaveAs_SafeDefaultName) {
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   base::ScopedTempDir temp_dir;
   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
   base::FilePath suggested_filename = temp_dir.GetPath().AppendASCII("foo");
@@ -332,6 +336,7 @@ IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest,
 
 IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest,
                        FileChooser_SaveAs_UnsafeDefaultName) {
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   base::ScopedTempDir temp_dir;
   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
   base::FilePath suggested_filename = temp_dir.GetPath().AppendASCII("foo");
@@ -366,6 +371,7 @@ IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest, FileChooser_SaveAs_Cancel) {
 // file is created. This MOTW prevents the file being opened without due
 // security warnings if the file is executable.
 IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest, FileChooser_Quarantine) {
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   base::ScopedTempDir temp_dir;
   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
   base::FilePath suggested_filename = temp_dir.GetPath().AppendASCII("foo");
@@ -392,6 +398,7 @@ IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTest, FileChooser_Quarantine) {
 
 IN_PROC_BROWSER_TEST_F(PPAPIFileChooserTestWithSBService,
                        FileChooser_SaveAs_DangerousExecutable_Allowed) {
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   safe_browsing_test_configuration_.default_result =
       DownloadProtectionService::DANGEROUS;
   safe_browsing_test_configuration_.result_map.insert(