[SystemInfo API] Rewrite DisplayInfoProvider without SystemInfoProvider.

chrome/browser/extensions/api/system_display/display_info_provider.cc

Index: chrome/browser/extensions/api/system_display/display_info_provider.cc
diff --git a/chrome/browser/extensions/api/system_display/display_info_provider.cc b/chrome/browser/extensions/api/system_display/display_info_provider.cc
index 064688db5694c3865aa6bde3f0ad9c8b48458474..d57bd15ce0a477cb723337ed4af2b47f92c87ccf 100644
--- a/chrome/browser/extensions/api/system_display/display_info_provider.cc
+++ b/chrome/browser/extensions/api/system_display/display_info_provider.cc
@@ -27,11 +27,9 @@ int RotationToDegrees(gfx::Display::Rotation rotation) {
   return 0;
 }
 
-// Creates new DisplayUnitInfo struct for |display| and adds it at the end of
-// |list|.
+// Creates new DisplayUnitInfo struct for |display|.
 extensions::api::system_display::DisplayUnitInfo*
-CreateDisplayUnitInfo(const gfx::Display& display,
-               int64 primary_display_id) {
+CreateDisplayUnitInfo(const gfx::Display& display, int64 primary_display_id) {
   extensions::api::system_display::DisplayUnitInfo* unit =
       new extensions::api::system_display::DisplayUnitInfo();
   const gfx::Rect& bounds = display.bounds();
@@ -52,59 +50,40 @@ CreateDisplayUnitInfo(const gfx::Display& display,
   return unit;
 }
 
+DisplayInfoProvider* g_display_info_provider = NULL;
+
 }  // namespace
 
-DisplayInfoProvider::DisplayInfoProvider() {
-}
 
-DisplayInfoProvider::~DisplayInfoProvider() {
-}
+DisplayInfoProvider::DisplayInfoProvider() {}
 
-// Static member intialization.
-base::LazyInstance<scoped_refptr<DisplayInfoProvider > >
-    DisplayInfoProvider::provider_ = LAZY_INSTANCE_INITIALIZER;
+DisplayInfoProvider::~DisplayInfoProvider() {}
 
-const DisplayInfo& DisplayInfoProvider::display_info() const {
-  return info_;
+DisplayInfoProvider* DisplayInfoProvider::Get() {
+  if (g_display_info_provider == NULL)
+    g_display_info_provider = new DisplayInfoProvider();
+  return g_display_info_provider;
 }
 
 void DisplayInfoProvider::InitializeForTesting(
-    scoped_refptr<DisplayInfoProvider> provider) {
-  DCHECK(provider.get() != NULL);
-  provider_.Get() = provider;
+    DisplayInfoProvider* display_info_provider) {
+  DCHECK(display_info_provider);

[oshima, 2013/09/10 21:49:52]

Note. While this works for browser tests, which runs its own process,
this doesn't work for unit tests where multiple tests are run within
one process. You may want to comment in the header, or
you can simply do "delete display_info_provider;". (I'm fine with either way)

[Haojian Wu, 2013/09/11 02:50:49]

Done. Added comments.

+  g_display_info_provider = display_info_provider;
 }
 
-void DisplayInfoProvider::RequestInfo(const RequestInfoCallback& callback) {
-  bool success = QueryInfo();
-
-  base::MessageLoopProxy::current()->PostTask(
-      FROM_HERE,
-      base::Bind(callback, success));
-}
-
-#if !defined(OS_WIN)
-bool DisplayInfoProvider::QueryInfo() {
-  info_.clear();
-
+DisplayInfo DisplayInfoProvider::GetAllDisplaysInfo() {
   // TODO(scottmg): Native is wrong http://crbug.com/133312
   gfx::Screen* screen = gfx::Screen::GetNativeScreen();
   int64 primary_id = screen->GetPrimaryDisplay().id();
   std::vector<gfx::Display> displays = screen->GetAllDisplays();
+  DisplayInfo all_displays;
   for (int i = 0; i < screen->GetNumDisplays(); ++i) {
     linked_ptr<extensions::api::system_display::DisplayUnitInfo> unit(
         CreateDisplayUnitInfo(displays[i], primary_id));
     UpdateDisplayUnitInfoForPlatform(displays[i], unit.get());
-    info_.push_back(unit);
+    all_displays.push_back(unit);
   }
-  return true;
-}
-#endif
-
-// static
-DisplayInfoProvider* DisplayInfoProvider::Get() {
-  if (provider_.Get().get() == NULL)
-    provider_.Get() = new DisplayInfoProvider();
-  return provider_.Get();
+  return all_displays;
 }
 
 }  // namespace extensions