Bug 1745308 - Only warn once if ClientWaitSync cannot return availability. r=gfx-reviewers,nical

This avoids spamming warnings across IPC that sometimes causes shmem
exhaustion.

Differential Revision: https://phabricator.services.mozilla.com/D133829

dom/canvas/ClientWebGLContext.cpp

@@ -5119,9 +5119,12 @@ GLenum ClientWebGLContext::ClientWaitSync(WebGLSyncJS& sync,
   const bool canBeAvailable =
       (sync.mCanBeAvailable || StaticPrefs::webgl_allow_immediate_queries());
   if (!canBeAvailable) {
-    EnqueueWarning(
-        "ClientWaitSync must return TIMEOUT_EXPIRED until control has"
-        " returned to the user agent's main loop.");
+    if (!sync.mHasWarnedNotAvailable) {
+      EnqueueWarning(
+          "ClientWaitSync must return TIMEOUT_EXPIRED until control has"
+          " returned to the user agent's main loop. (only warns once)");
+      sync.mHasWarnedNotAvailable = true;
+    }
     return LOCAL_GL_TIMEOUT_EXPIRED;
   }
 

dom/canvas/ClientWebGLContext.h

@@ -485,6 +485,7 @@ class WebGLSyncJS final : public nsWrapperCache,
   friend class webgl::AvailabilityRunnable;
 
   bool mCanBeAvailable = false;
+  bool mHasWarnedNotAvailable = false;
   bool mSignaled = false;
 
  public: