[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..5a3138e436d83515fd60fdffc8a9d51798175e57 100644
--- a/chrome/browser/extensions/api/system_display/display_info_provider.cc
+++ b/chrome/browser/extensions/api/system_display/display_info_provider.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/extensions/api/system_display/display_info_provider.h"
 
+#include "base/lazy_instance.h"
 #include "base/strings/string_number_conversions.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/screen.h"
@@ -27,11 +28,9 @@ 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();
@@ -54,57 +53,39 @@ CreateDisplayUnitInfo(const gfx::Display& display,
 
 }  // namespace
 
-DisplayInfoProvider::DisplayInfoProvider() {
-}
+static base::LazyInstance<scoped_ptr<DisplayInfoProvider> >

[Hongbo Min, 2013/09/05 08:43:36]

Why not directly use DisplayInfoProvider instead of scoped_ptr?

[Haojian Wu, 2013/09/05 08:52:22]

If uing DisplayInfoProvider directly, how to set a custom
|display_info_provider| instance for Test in InitializeForTest()? 

+  g_display_info_provider = LAZY_INSTANCE_INITIALIZER;
 
-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.Get().get() == NULL)
+    g_display_info_provider.Get() = scoped_ptr<DisplayInfoProvider>(
+        new DisplayInfoProvider);
+  return g_display_info_provider.Get().get();
 }
 
 void DisplayInfoProvider::InitializeForTesting(
-    scoped_refptr<DisplayInfoProvider> provider) {
-  DCHECK(provider.get() != NULL);
-  provider_.Get() = provider;
-}
-
-void DisplayInfoProvider::RequestInfo(const RequestInfoCallback& callback) {
-  bool success = QueryInfo();
-
-  base::MessageLoopProxy::current()->PostTask(
-      FROM_HERE,
-      base::Bind(callback, success));
+    DisplayInfoProvider* display_info_provider) {
+  g_display_info_provider.Get() = scoped_ptr<DisplayInfoProvider>(
+      display_info_provider);
 }
 
-#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