Bug 1710473 - Remove hal::SetProcessPrioritySupported(). r=gsvelto,geckoview-reviewers,aklotz

As far as I can see, all this does is protect the user from
running some useless code if they manually enable the priority
manager using a pref on an OS that doesn't support it. The
upside of allowing this is that it makes it possible to debug
the priority manager on OSX and Linux with just a pref flip.

Differential Revision: https://phabricator.services.mozilla.com/D114767

build/win32/orderfile.txt

@@ -725,7 +725,6 @@ NS_CycleCollectorSuspect3
 ?RegisterGhostWindowsDistinguishedAmount@mozilla@@YA?AW4nsresult@@P6A_JXZ@Z
 ?Init@SVGElementFactory@dom@mozilla@@SAXXZ
 ?FromMessagesToSharedParent@SharedMessageBody@dom@mozilla@@SA_NAAV?$nsTArray@VMessageData@dom@mozilla@@@@AAV?$FallibleTArray@V?$RefPtr@VSharedMessageBody@dom@mozilla@@@@@@W4TransferringSupport@StructuredCloneHolder@23@@Z
-?SetProcessPrioritySupported@hal@mozilla@@YA_NXZ
 ?Get@LogModule@mozilla@@SAPAV12@PBD@Z
 ?SetProcessPriority@hal_impl@mozilla@@YAXHW4ProcessPriority@hal@2@@Z
 ?GetHalLog@hal@mozilla@@YAPAVLogModule@2@XZ

build/win64/orderfile.txt

@@ -731,7 +731,6 @@ NS_CycleCollectorSuspect3
 ?RegisterGhostWindowsDistinguishedAmount@mozilla@@YA?AW4nsresult@@P6A_JXZ@Z
 ?Init@SVGElementFactory@dom@mozilla@@SAXXZ
 ?FromMessagesToSharedParent@SharedMessageBody@dom@mozilla@@SA_NAEAV?$nsTArray@VMessageData@dom@mozilla@@@@AEAV?$FallibleTArray@V?$RefPtr@VSharedMessageBody@dom@mozilla@@@@@@W4TransferringSupport@StructuredCloneHolder@23@@Z
-?SetProcessPrioritySupported@hal@mozilla@@YA_NXZ
 ?Get@LogModule@mozilla@@SAPEAV12@PEBD@Z
 ?SetProcessPriority@hal_impl@mozilla@@YAXHW4ProcessPriority@hal@2@@Z
 ?GetHalLog@hal@mozilla@@YAPEAVLogModule@2@XZ

dom/ipc/ProcessPriorityManager.cpp

@@ -307,7 +307,6 @@ void ProcessPriorityManagerImpl::PrefChangedCallback(const char* aPref,
 /* static */
 bool ProcessPriorityManagerImpl::PrefsEnabled() {
   return StaticPrefs::dom_ipc_processPriorityManager_enabled() &&
-         hal::SetProcessPrioritySupported() &&
          !StaticPrefs::dom_ipc_tabs_disabled();
 }
 

hal/Hal.cpp

@@ -417,10 +417,6 @@ void UnlockScreenOrientation() {
   PROXY_IF_SANDBOXED(UnlockScreenOrientation());
 }
 
-bool SetProcessPrioritySupported() {
-  RETURN_PROXY_IF_SANDBOXED(SetProcessPrioritySupported(), false);
-}
-
 void SetProcessPriority(int aPid, ProcessPriority aPriority) {
   // n.b. The sandboxed implementation crashes; SetProcessPriority works only
   // from the main process.

hal/Hal.h

@@ -242,12 +242,6 @@ void NotifyScreenConfigurationChange(
  */
 void UnlockScreenOrientation();
 
-/**
- * Return true if the current platform supports the setting of process
- * priority.
- */
-bool SetProcessPrioritySupported();
-
 /**
  * Set the priority of the given process.
  *

hal/android/AndroidProcessPriority.cpp

@@ -29,8 +29,6 @@ ToJavaPriorityLevel(const ProcessPriority aPriority) {
 namespace mozilla {
 namespace hal_impl {
 
-bool SetProcessPrioritySupported() { return true; }
-
 void SetProcessPriority(int aPid, ProcessPriority aPriority) {
   if (aPriority == PROCESS_PRIORITY_PARENT_PROCESS) {
     // This is the parent process itself, which we do not control.

hal/fallback/FallbackProcessPriority.cpp

@@ -10,8 +10,6 @@ using namespace mozilla::hal;
 namespace mozilla {
 namespace hal_impl {
 
-bool SetProcessPrioritySupported() { return false; }
-
 void SetProcessPriority(int aPid, ProcessPriority aPriority) {
   HAL_LOG("FallbackProcessPriority - SetProcessPriority(%d, %s)\n", aPid,
           ProcessPriorityToString(aPriority));

hal/sandbox/SandboxHal.cpp

@@ -132,10 +132,6 @@ void SetProcessPriority(int aPid, ProcessPriority aPriority) {
   MOZ_CRASH("Only the main process may set processes' priorities.");
 }
 
-bool SetProcessPrioritySupported() {
-  MOZ_CRASH("Only the main process may call SetProcessPrioritySupported().");
-}
-
 class HalParent : public PHalParent,
                   public BatteryObserver,
                   public NetworkObserver,

hal/windows/WindowsProcessPriority.cpp

@@ -12,8 +12,6 @@ using namespace mozilla::hal;
 namespace mozilla {
 namespace hal_impl {
 
-bool SetProcessPrioritySupported() { return true; }
-
 void SetProcessPriority(int aPid, ProcessPriority aPriority) {
   HAL_LOG("WindowsProcessPriority - SetProcessPriority(%d, %s)\n", aPid,
           ProcessPriorityToString(aPriority));