Add the basic code skeleton for system info event router

chrome/browser/extensions/api/system_info_storage/system_info_storage_apitest.cc

Index: chrome/browser/extensions/api/system_info_storage/system_info_storage_apitest.cc
diff --git a/chrome/browser/extensions/api/system_info_storage/system_info_storage_apitest.cc b/chrome/browser/extensions/api/system_info_storage/system_info_storage_apitest.cc
index 9d467065b64c6b7c75ad9e932199b5b5a417ae2d..18868f7cf778d182dadee6220e3f06ff71a2d046 100644
--- a/chrome/browser/extensions/api/system_info_storage/system_info_storage_apitest.cc
+++ b/chrome/browser/extensions/api/system_info_storage/system_info_storage_apitest.cc
@@ -3,8 +3,11 @@
 // found in the LICENSE file.
 #include "base/command_line.h"
 #include "base/message_loop.h"
+#include "base/timer.h"
 #include "chrome/browser/extensions/api/system_info_storage/storage_info_provider.h"
 #include "chrome/browser/extensions/extension_apitest.h"
+#include "chrome/browser/extensions/extension_test_message_listener.h"
+#include "chrome/browser/extensions/system_info_event_router.h"
 #include "chrome/common/chrome_switches.h"
 
 namespace extensions {
@@ -12,10 +15,17 @@ namespace extensions {
 using api::experimental_system_info_storage::StorageInfo;
 using api::experimental_system_info_storage::StorageUnitInfo;
 
+const int kDefaultInterval = 200; // default interval is 200ms.

[Mihai Parparita -not on Chrome, 2012/08/31 01:01:00]

Instead of needing a comment, can you make the constant name kDefaultIntervalMs
so that it's more obvious from the name what the units are?

[Hongbo Min, 2012/08/31 15:29:53]

Done.

+const int kAvailableCapacityBase = 10000;

[Mihai Parparita -not on Chrome, 2012/08/31 01:01:00]

Ditto here (add a "Bytes" suffix to the name) and below.

[Hongbo Min, 2012/08/31 15:29:53]

Done.

+const int kChangeStep = 10;
+
 class MockStorageInfoProvider : public StorageInfoProvider {
  public:
-  MockStorageInfoProvider() {}
-  virtual ~MockStorageInfoProvider() {}
+  MockStorageInfoProvider() : timer_(NULL), is_watching_(false) {
+  }
+  virtual ~MockStorageInfoProvider() {
+    StopWatching();
+  }
 
   virtual bool QueryInfo(StorageInfo* info) OVERRIDE {
     info->units.clear();
@@ -30,10 +40,45 @@ class MockStorageInfoProvider : public StorageInfoProvider {
     return true;
   }
 
-  virtual bool QueryUnitInfo(const std::string& id,
+  virtual bool QueryUnitInfo(const FilePath::StringType& path,
                              StorageUnitInfo* info) OVERRIDE {
     return false;
   }
+
+  bool StartWatching() {
+    if (is_watching_) return false;
+
+    timer_ = new base::RepeatingTimer<MockStorageInfoProvider>();
+    // Start the timer to emulate storage.onChanged event.
+    timer_->Start(FROM_HERE,
+                  base::TimeDelta::FromMilliseconds(kDefaultInterval),
+                  this, &MockStorageInfoProvider::OnTimeoutEvent);
+
+    is_watching_ = true;
+    return true;
+  }
+
+  bool StopWatching() {
+    if (!is_watching_) return false;
+    is_watching_ = false;
+    timer_->Stop();
+    delete timer_;

[Mihai Parparita -not on Chrome, 2012/08/31 01:01:00]

Since you only call StopWatching from the destructor, it's preferable to make
timer_ into a scoped_ptr and just let its destruction stop the timer.

[Hongbo Min, 2012/08/31 15:29:53]

Done.

+    timer_ = NULL;
+    return true;
+  }
+
+ private:
+  void OnTimeoutEvent() {
+    static int count;
+    SystemInfoEventRouter::GetInstance()->
+      OnStorageAvailableCapacityChanged("/dev/sda1",
+          kAvailableCapacityBase - count * kChangeStep);
+    count++;
+  }
+
+  // Use a repeating timer to emulate storage free space change event.
+  base::RepeatingTimer<MockStorageInfoProvider>* timer_;
+  bool  is_watching_;

[Mihai Parparita -not on Chrome, 2012/08/31 01:01:00]

Nit: extra space after bool.

[Hongbo Min, 2012/08/31 15:29:53]

Done.

 };
 
 class SystemInfoStorageApiTest: public ExtensionApiTest {
@@ -56,9 +101,14 @@ class SystemInfoStorageApiTest: public ExtensionApiTest {
 };
 
 IN_PROC_BROWSER_TEST_F(SystemInfoStorageApiTest, Storage) {
-  StorageInfoProvider* provider = new MockStorageInfoProvider();
+  MockStorageInfoProvider* provider = new MockStorageInfoProvider();
   StorageInfoProvider::InitializeForTesting(provider);
-  ASSERT_TRUE(RunExtensionTest("systeminfo/storage")) << message_;
+
+  ExtensionTestMessageListener listener("ready", true);
+  ASSERT_TRUE(LoadExtension(test_data_dir_.AppendASCII("systeminfo/storage")));
+  EXPECT_TRUE(listener.WaitUntilSatisfied());
+  provider->StartWatching();
+  listener.Reply("go");
 }
 
 } // namespace extensions