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

chrome/browser/devtools/devtools_sanity_browsertest.cc

Index: chrome/browser/devtools/devtools_sanity_browsertest.cc
diff --git a/chrome/browser/devtools/devtools_sanity_browsertest.cc b/chrome/browser/devtools/devtools_sanity_browsertest.cc
index 700ebf862fd7e3ad17a2926485ddb158546d457b..1bca1973655b5b5898eb5750cc9403c2a0844b9c 100644
--- a/chrome/browser/devtools/devtools_sanity_browsertest.cc
+++ b/chrome/browser/devtools/devtools_sanity_browsertest.cc
@@ -23,6 +23,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/task_scheduler/post_task.h"
 #include "base/test/test_timeouts.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ -597,6 +598,7 @@ class DevToolsExtensionTest : public DevToolsSanityTest,
   const Extension* GetExtensionByPath(
       const extensions::ExtensionSet& extensions,
       const base::FilePath& path) {
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
     base::FilePath extension_path = base::MakeAbsoluteFilePath(path);
     EXPECT_TRUE(!extension_path.empty());
     for (const scoped_refptr<const Extension>& extension : extensions) {