Mixed Content: Migrate ResourceFetcher to the static mixed content checker.

LayoutTests/http/tests/security/mixedContent/insecure-audio-video-in-main-frame-expected.txt

Index: LayoutTests/http/tests/security/mixedContent/insecure-audio-video-in-main-frame-expected.txt
diff --git a/LayoutTests/http/tests/security/mixedContent/insecure-audio-video-in-main-frame-expected.txt b/LayoutTests/http/tests/security/mixedContent/insecure-audio-video-in-main-frame-expected.txt
index a03e28321f7112403a22316aeaf2cc7ec262c462..142bb1026cf9de7075ec6b6a53f9f5753a045ff9 100644
--- a/LayoutTests/http/tests/security/mixedContent/insecure-audio-video-in-main-frame-expected.txt
+++ b/LayoutTests/http/tests/security/mixedContent/insecure-audio-video-in-main-frame-expected.txt
@@ -1,5 +1,3 @@
-CONSOLE WARNING: The page at 'https://127.0.0.1:8443/security/mixedContent/resources/frame-with-insecure-audio-video.html' was loaded over HTTPS, but displayed insecure content from 'http://127.0.0.1:8080/resources/test.mp4': this content should also be loaded over HTTPS.
-
-CONSOLE WARNING: The page at 'https://127.0.0.1:8443/security/mixedContent/resources/frame-with-insecure-audio-video.html' was loaded over HTTPS, but displayed insecure content from 'http://127.0.0.1:8080/resources/test.mp4': this content should also be loaded over HTTPS.
-
+CONSOLE WARNING: Mixed Content: The page at 'https://127.0.0.1:8443/security/mixedContent/resources/frame-with-insecure-audio-video.html' was loaded over HTTPS, but requested an insecure video 'http://127.0.0.1:8080/resources/test.mp4'. This content should also be served over HTTPS.
+CONSOLE WARNING: Mixed Content: The page at 'https://127.0.0.1:8443/security/mixedContent/resources/frame-with-insecure-audio-video.html' was loaded over HTTPS, but requested an insecure video 'http://127.0.0.1:8080/resources/test.mp4'. This content should also be served over HTTPS.
 This test opens a window that loads insecure HTML5 audio and video. We should trigger a mixed content callback because the main frame in the window is HTTPS but is displaying insecure content.