Don't send a SHChangeNotify for creating an app icon when creating a shortcut.

This CL fixes an issue with the initial app sync on sign-in causing many
taskbar flashes due to icon creation always sending a SHChangeNotify.

This shouldn't be necessary for icon creation due to shortcut creation so
avoid SHChangeNotify in this case.

BUG=470002

Review URL: https://codereview.chromium.org/1026113003

Cr-Commit-Position: refs/heads/master@{#322324}

chrome/browser/web_applications/update_shortcut_worker_win.cc

@@ -192,7 +192,7 @@ void UpdateShortcutWorker::UpdateShortcutsOnFileThread() {
 
   base::FilePath icon_file =
       web_app::internals::GetIconFilePath(web_app_path, shortcut_info_.title);
-  web_app::internals::CheckAndSaveIcon(icon_file, shortcut_info_.favicon);
+  web_app::internals::CheckAndSaveIcon(icon_file, shortcut_info_.favicon, true);
 
   // Update existing shortcuts' description, icon and app id.
   CheckExistingShortcuts();

chrome/browser/web_applications/web_app_win.cc

@@ -183,7 +183,8 @@ bool CreateShortcutsInPaths(
   // Generates file name to use with persisted ico and shortcut file.
   base::FilePath icon_file =
       web_app::internals::GetIconFilePath(web_app_path, shortcut_info.title);
-  if (!web_app::internals::CheckAndSaveIcon(icon_file, shortcut_info.favicon)) {
+  if (!web_app::internals::CheckAndSaveIcon(icon_file, shortcut_info.favicon,
+                                            false)) {
     return false;
   }
 
@@ -357,7 +358,7 @@ void CreateIconAndSetRelaunchDetails(const base::FilePath& web_app_path,
     return;
 
   ui::win::SetAppIconForWindow(icon_file.value(), hwnd);
-  web_app::internals::CheckAndSaveIcon(icon_file, shortcut_info.favicon);
+  web_app::internals::CheckAndSaveIcon(icon_file, shortcut_info.favicon, true);
 }
 
 void OnShortcutInfoLoadedForSetRelaunchDetails(
@@ -543,7 +544,7 @@ base::FilePath CreateShortcutInWebAppDir(const base::FilePath& web_app_dir,
   } else {
     internals::CheckAndSaveIcon(
         internals::GetIconFilePath(web_app_dir, shortcut_info.title),
-        shortcut_info.favicon);
+        shortcut_info.favicon, true);
   }
   return web_app_dir_shortcut;
 }
@@ -564,23 +565,22 @@ void UpdateShortcutsForAllApps(Profile* profile,
 
 namespace internals {
 
-// Saves |image| to |icon_file| if the file is outdated and refresh shell's
-// icon cache to ensure correct icon is displayed. Returns true if icon_file
-// is up to date or successfully updated.
 bool CheckAndSaveIcon(const base::FilePath& icon_file,
-                      const gfx::ImageFamily& image) {
-  if (ShouldUpdateIcon(icon_file, image)) {
-    if (SaveIconWithCheckSum(icon_file, image)) {
-      // Refresh shell's icon cache. This call is quite disruptive as user would
-      // see explorer rebuilding the icon cache. It would be great that we find
-      // a better way to achieve this.
-      SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST | SHCNF_FLUSHNOWAIT,
-                     NULL, NULL);
-    } else {
-      return false;
-    }
-  }
+                      const gfx::ImageFamily& image,
+                      bool refresh_shell_icon_cache) {
+  if (!ShouldUpdateIcon(icon_file, image))
+    return true;
+
+  if (!SaveIconWithCheckSum(icon_file, image))
+    return false;
 
+  if (refresh_shell_icon_cache) {
+    // Refresh shell's icon cache. This call is quite disruptive as user would
+    // see explorer rebuilding the icon cache. It would be great that we find
+    // a better way to achieve this.
+    SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST | SHCNF_FLUSHNOWAIT, NULL,
+                   NULL);
+  }
   return true;
 }
 
@@ -674,7 +674,7 @@ void UpdatePlatformShortcuts(
 
   // Update the icon if necessary.
   base::FilePath icon_file = GetIconFilePath(web_app_path, shortcut_info.title);
-  CheckAndSaveIcon(icon_file, shortcut_info.favicon);
+  CheckAndSaveIcon(icon_file, shortcut_info.favicon, true);
 }
 
 void DeletePlatformShortcuts(const base::FilePath& web_app_path,

chrome/browser/web_applications/web_app_win.h

@@ -37,8 +37,15 @@ void UpdateRelaunchDetailsForApp(Profile* profile,
 
 namespace internals {
 
+// Saves |image| to |icon_file| if the file is outdated. Returns true if
+// icon_file is up to date or successfully updated.
+// If |refresh_shell_icon_cache| is true, the shell's icon cache will be
+// refreshed, ensuring the correct icon is displayed, but causing a flicker.
+// Refreshing the icon cache is not necessary on shortcut creation as the shell
+// will be notified when the shortcut is created.
 bool CheckAndSaveIcon(const base::FilePath& icon_file,
-                      const gfx::ImageFamily& image);
+                      const gfx::ImageFamily& image,
+                      bool refresh_shell_icon_cache);
 
 base::FilePath GetIconFilePath(const base::FilePath& web_app_path,
                                const base::string16& title);