Make browsing context keywords case-insensitive.

third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp

Index: third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp b/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
index cae0bb12134adec74ada3184674c5fb56990de92..197ceb6e2f143fa157b17dac14e446be9eb4325c 100644
--- a/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
@@ -1587,9 +1587,9 @@ DOMWindow* LocalDOMWindow::open(const String& urlString,
   // Get the target frame for the special cases of _top and _parent.
   // In those cases, we schedule a location change right now and return early.
   Frame* targetFrame = nullptr;
-  if (frameName == "_top") {
+  if (equalIgnoringCase(frameName, "_top")) {

[tkent, 2017/03/30 05:57:00]

Please use equalIgnoringASCIICase(). equalIgnoringCase() is not for ASCII
case-insensitive.

     targetFrame = frame()->tree().top();
-  } else if (frameName == "_parent") {
+  } else if (equalIgnoringCase(frameName, "_parent")) {
     if (Frame* parent = frame()->tree().parent())
       targetFrame = parent;
     else