Use ThreadChecker rather than DCHECK_CURRENTLY_ON.

chrome/test/base/testing_profile.cc

Index: chrome/test/base/testing_profile.cc
diff --git a/chrome/test/base/testing_profile.cc b/chrome/test/base/testing_profile.cc
index 64d44dadcb5baeec2ba9eceff83d560f65d23a2f..878d2a4b4121e8882026d4ee233da2bd6eab8e47 100644
--- a/chrome/test/base/testing_profile.cc
+++ b/chrome/test/base/testing_profile.cc
@@ -830,6 +830,9 @@ content::ResourceContext* TestingProfile::GetResourceContext() {
 }
 
 HostContentSettingsMap* TestingProfile::GetHostContentSettingsMap() {
+  DCHECK(!content::BrowserThread::IsThreadInitialized(

[Paweł Hajdan Jr., 2014/10/20 09:11:51]

This seems the only place in this patch where IsThreadInitialized is used. Why
is that needed?

[Jun Mukai, 2014/10/20 17:02:51]

I copied this check from TestingProfile::Init().  I haven't tried the case
without this check, but I believe that some unit tests may not run
BrowserThread::UI, and enforcing to run BrowserThread for any tests using
TestingProfile is a bad idea.

[Paweł Hajdan Jr., 2014/10/21 09:30:58]

If it's really needed, please extract it to a common method.
Could you try it?
Why?

[Jun Mukai, 2014/10/22 06:30:13]

Tried and I was wrong. Changed to use DCHECK_CURRENTLY_ON.  PTAL.

+             content::BrowserThread::UI) ||
+         content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   if (!host_content_settings_map_.get()) {
     host_content_settings_map_ = new HostContentSettingsMap(GetPrefs(), false);
 #if defined(ENABLE_EXTENSIONS)