[Fuchsia] Update font paths in content_shell

test fonts are now packages as part of app package on fuchsia, so they
can be loaded from /pkg/test_fonts.

Bug: 787020
Change-Id: Ie8507d42cb92b518b83193a448643145c3539fe1
Reviewed-on: https://chromium-review.googlesource.com/1054573Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557915}

content/shell/app/blink_test_platform_support_fuchsia.cc

@@ -18,9 +18,9 @@ bool BlinkTestPlatformInitialize() {
   // Initialize Skia with the font configuration files crafted for layout tests.
   SkFontMgr_Android_CustomFonts custom;
   custom.fSystemFontUse = SkFontMgr_Android_CustomFonts::kOnlyCustom;
-  custom.fBasePath = "/system/fonts/";
-  custom.fFontsXml = "/system/fonts/fonts.xml";
-  custom.fFallbackFontsXml = "/system/fonts/fonts_fallback.xml";
+  custom.fBasePath = "/pkg/test_fonts/";
+  custom.fFontsXml = "/pkg/test_fonts/android_main_fonts.xml";
+  custom.fFallbackFontsXml = "/pkg/test_fonts/android_fallback_fonts.xml";
   custom.fIsolated = false;
 
   SetDefaultSkiaFactory(SkFontMgr_New_Android(&custom));