[M90-LTS] Fix multidraw validation drawcount + offset out of bounds

(cherry picked from commit 7d0a12c)

Bug: 1219886
Change-Id: I8a84664150758370d9a77ee22ac5549bead0e37e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2977850
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#895423}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3041457
Reviewed-by: Jana Grill <janagrill@google.com>
Owners-Override: Jana Grill <janagrill@google.com>
Commit-Queue: Roger Felipe Zanoni da Silva <rzanoni@google.com>
Cr-Commit-Position: refs/branch-heads/4430@{#1542}
Cr-Branched-From: e5ce7dc-refs/heads/master@{#857950}

third_party/blink/renderer/modules/webgl/webgl_multi_draw_common.cc

@@ -34,6 +34,11 @@ bool WebGLMultiDrawCommon::ValidateArray(WebGLExtensionScopedContext* scoped,
                                          outOfBoundsDescription);
     return false;
   }
+  if (static_cast<uint64_t>(drawcount) + offset > size) {
+    scoped->Context()->SynthesizeGLError(GL_INVALID_OPERATION, function_name,
+                                         "drawcount plus offset out of bounds");
+    return false;
+  }
   return true;
 }