import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1015664. Part 1: Remove NS_HIDDEN_() usage. r=bsmedberg (afd6618205)
- Bug 1015664. Part 2: Remove some NS_HIDDEN usage. r=bsmedberg (0222fb6e5a)
- Bug 1041516 part 2: reset the "check for default browser" pref to true when setting ourselves as the default browser, r=Gijs (3ba909462c)
- Bug 1041516 part 1: clean up pref code in shell service, r=bsmedberg (b9bfe88eca)
- Bug 1191250 - Defer showing the default browser prompt to 2nd run (and only show it a maximum of three times). r=jimm (f7c75754bf)
- missingbits of 869836 AssignLiteral AppendLiteral (74ab86cdb4)
- Bug 1171361 - Fix -Wunreachable-code-break warnings in shell/nsMacShellService.cpp. r=mak (a38a5484a7)
- code sytle and missing bits of 784739 - Switch from NULL (b45cba6988)
- Bug 962709 - Fix about:home's sync entry point to work with about FxAccounts r=markh (5894b3a94b)
- missing bit of Bug 738646 - Show apps button by default on about:home (3157ac5329)
- partial of Bug 1101147 - Update about:newtab search styling. (464c18432d)
- Bug 1041663 - handle dragging the global webrtc sharing indicator, r=dolske. (097d61d263)
- Bug 1042163 - Visual issues with the global indicator for screen/device sharing, r=Gijs. (c27f666211)

browser/components/shell/nsWindowsShellService.cpp

@@ -279,20 +279,15 @@ nsWindowsShellService::ShortcutMaintenance()
     return NS_ERROR_UNEXPECTED;
 
   NS_NAMED_LITERAL_CSTRING(prefName, "browser.taskbar.lastgroupid");
-  nsCOMPtr<nsIPrefService> prefs =
+  nsCOMPtr<nsIPrefBranch> prefs =
     do_GetService(NS_PREFSERVICE_CONTRACTID);
   if (!prefs)
     return NS_ERROR_UNEXPECTED;
 
-  nsCOMPtr<nsIPrefBranch> prefBranch;
-  prefs->GetBranch(nullptr, getter_AddRefs(prefBranch));
-  if (!prefBranch)
-    return NS_ERROR_UNEXPECTED;
-
   nsCOMPtr<nsISupportsString> prefString;
-  rv = prefBranch->GetComplexValue(prefName.get(),
-                                   NS_GET_IID(nsISupportsString),
-                                   getter_AddRefs(prefString));
+  rv = prefs->GetComplexValue(prefName.get(),
+                              NS_GET_IID(nsISupportsString),
+                              getter_AddRefs(prefString));
   if (NS_SUCCEEDED(rv)) {
     nsAutoString version;
     prefString->GetData(version);
@@ -308,9 +303,9 @@ nsWindowsShellService::ShortcutMaintenance()
     return rv;
 
   prefString->SetData(appId);
-  rv = prefBranch->SetComplexValue(prefName.get(),
-                                   NS_GET_IID(nsISupportsString),
-                                   prefString);
+  rv = prefs->SetComplexValue(prefName.get(),
+                              NS_GET_IID(nsISupportsString),
+                              prefString);
   if (NS_FAILED(rv)) {
     NS_WARNING("Couldn't set last user model id!");
     return NS_ERROR_UNEXPECTED;
@@ -743,30 +738,84 @@ nsWindowsShellService::SetDefaultBrowser(bool aClaimAllTypes, bool aForAllUsers)
   nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
   if (prefs) {
     (void) prefs->SetBoolPref(PREF_CHECKDEFAULTBROWSER, true);
+    // Reset the number of times the dialog should be shown
+    // before it is silenced.
+    (void) prefs->SetIntPref(PREF_DEFAULTBROWSERCHECKCOUNT, 0);
   }
 
   return rv;
 }
 
+NS_IMETHODIMP
+nsWindowsShellService::GetShouldSkipCheckDefaultBrowser(bool* aResult)
+{
+  NS_ENSURE_ARG_POINTER(aResult);
+
+  nsresult rv;
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = prefs->GetBoolPref(PREF_SKIPDEFAULTBROWSERCHECK, aResult);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (*aResult) {
+    // Only skip the default browser check once. The next attempt in
+    // a new session should proceed.
+    return prefs->SetBoolPref(PREF_SKIPDEFAULTBROWSERCHECK, false);
+  }
+
+  int32_t defaultBrowserCheckCount;
+  rv = prefs->GetIntPref(PREF_DEFAULTBROWSERCHECKCOUNT,
+                         &defaultBrowserCheckCount);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (defaultBrowserCheckCount < 3) {
+    *aResult = false;
+    return prefs->SetIntPref(PREF_DEFAULTBROWSERCHECKCOUNT,
+                             defaultBrowserCheckCount + 1);
+  }
+
+  // Disable the default browser check after three attempts.
+  // Don't modify PREF_CHECKDEFAULTBROWSER since that is a
+  // user-initiated action and it shouldn't get re-enabled
+  // if it has been user disabled.
+  *aResult = true;
+  return rv;
+}
+
 NS_IMETHODIMP
 nsWindowsShellService::GetShouldCheckDefaultBrowser(bool* aResult)
 {
   NS_ENSURE_ARG_POINTER(aResult);
 
-  // If we've already checked, the browser has been started and this is a 
+  // If we've already checked, the browser has been started and this is a
   // new window open, and we don't want to check again.
   if (mCheckedThisSession) {
     *aResult = false;
     return NS_OK;
   }
 
-  nsCOMPtr<nsIPrefBranch> prefs;
   nsresult rv;
-  nsCOMPtr<nsIPrefService> pserve(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
-  NS_ENSURE_SUCCESS(rv, rv);
+#ifndef RELEASE_BUILD
+  bool skipDefaultBrowserCheck;
+  rv = GetShouldSkipCheckDefaultBrowser(&skipDefaultBrowserCheck);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (skipDefaultBrowserCheck) {
+    *aResult = false;
+    return rv;
+  }
+#endif
 
-  rv = pserve->GetBranch("", getter_AddRefs(prefs));
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
 
   return prefs->GetBoolPref(PREF_CHECKDEFAULTBROWSER, aResult);
 }
@@ -774,14 +823,11 @@ nsWindowsShellService::GetShouldCheckDefaultBrowser(bool* aResult)
 NS_IMETHODIMP
 nsWindowsShellService::SetShouldCheckDefaultBrowser(bool aShouldCheck)
 {
-  nsCOMPtr<nsIPrefBranch> prefs;
   nsresult rv;
-
-  nsCOMPtr<nsIPrefService> pserve(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
-  NS_ENSURE_SUCCESS(rv, rv);
-  
-  rv = pserve->GetBranch("", getter_AddRefs(prefs));
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
 
   return prefs->SetBoolPref(PREF_CHECKDEFAULTBROWSER, aShouldCheck);
 }