Add the Windows.IsPinnedToTaskbar metric.

chrome/browser/shell_integration_win.h

Index: chrome/browser/shell_integration_win.h
diff --git a/chrome/browser/shell_integration_win.h b/chrome/browser/shell_integration_win.h
index d609ea0e751d89dd394a3aeede58a3286504ece0..3d81886fcd413aad42c34563885d70952cb7025f 100644
--- a/chrome/browser/shell_integration_win.h
+++ b/chrome/browser/shell_integration_win.h
@@ -57,6 +57,10 @@ base::string16 GetAppModelIdForProfile(const base::string16& app_name,
 // calling GetAppModelIdForProfile() with ShellUtil::GetAppId() as app_name.
 base::string16 GetChromiumModelIdForProfile(const base::FilePath& profile_path);
 
+// Records the pinned state of the current executable into a histogram. Must be
+// called on the IO thread.
+void RecordIsPinnedToTaskbarHistogram();
+
 // Migrates existing chrome taskbar pins by tagging them with correct app id.
 // see http://crbug.com/28104
 void MigrateTaskbarPins();