core/platform: Include wtf files using "wtf/foo.h" form.

Source/core/platform/text/cf/StringImplCF.cpp

Index: Source/core/platform/text/cf/StringImplCF.cpp
diff --git a/Source/core/platform/text/cf/StringImplCF.cpp b/Source/core/platform/text/cf/StringImplCF.cpp
index 55f10d208c4cc8ede1a7dcc2213e9e4cfd62f061..2c2ed14cadcc92b589477a068f9d4569ee8c5e7a 100644
--- a/Source/core/platform/text/cf/StringImplCF.cpp
+++ b/Source/core/platform/text/cf/StringImplCF.cpp
@@ -19,15 +19,15 @@
  */
 
 #include "config.h"
-#include <wtf/text/StringImpl.h>
+#include "wtf/text/StringImpl.h"
 
 #if USE(CF)
 
 #include <CoreFoundation/CoreFoundation.h>
-#include <wtf/MainThread.h>
-#include <wtf/PassRefPtr.h>
-#include <wtf/RetainPtr.h>
-#include <wtf/Threading.h>
+#include "wtf/MainThread.h"
+#include "wtf/PassRefPtr.h"
+#include "wtf/RetainPtr.h"
+#include "wtf/Threading.h"
 
 namespace WTF {