third_party/WebKit: fix typos found in comments

third_party/WebKit/Source/core/loader/MixedContentChecker.cpp

Index: third_party/WebKit/Source/core/loader/MixedContentChecker.cpp
diff --git a/third_party/WebKit/Source/core/loader/MixedContentChecker.cpp b/third_party/WebKit/Source/core/loader/MixedContentChecker.cpp
index fdcc09b14a13bba18e331b1fa85bb1848942e2f5..2d9f656a0e207ffdaf89f10c195443da51bd1efc 100644
--- a/third_party/WebKit/Source/core/loader/MixedContentChecker.cpp
+++ b/third_party/WebKit/Source/core/loader/MixedContentChecker.cpp
@@ -49,7 +49,7 @@ static void measureStricterVersionOfIsMixedContent(LocalFrame* frame, const KURL
 {
     // We're currently only checking for mixed content in `https://*` contexts.
     // What about other "secure" contexts the SchemeRegistry knows about? We'll
-    // use this method to measure the occurance of non-webby mixed content to
+    // use this method to measure the occurrence of non-webby mixed content to
     // make sure we're not breaking the world without realizing it.
     SecurityOrigin* origin = frame->document()->securityOrigin();
     if (MixedContentChecker::isMixedContent(origin, url)) {