Add missing .h files to .gn files that have a .cc file next to it in the gn file already.

third_party/WebKit/Source/platform/wtf/BUILD.gn

Index: third_party/WebKit/Source/platform/wtf/BUILD.gn
diff --git a/third_party/WebKit/Source/platform/wtf/BUILD.gn b/third_party/WebKit/Source/platform/wtf/BUILD.gn
index 75752cb23dbc71af716377bc0a59b35ddd8bfb2c..a5c22bc21b4c31862c1e029f20ab1c5b30ef4f6d 100644
--- a/third_party/WebKit/Source/platform/wtf/BUILD.gn
+++ b/third_party/WebKit/Source/platform/wtf/BUILD.gn
@@ -193,6 +193,7 @@ source_set("platform_wtf") {
     "text/StringOperators.h",
     "text/StringStatics.cpp",
     "text/StringStatics.h",
+    "text/StringStatics.h",
     "text/StringToNumber.cpp",
     "text/StringToNumber.h",
     "text/StringUTF8Adaptor.h",
@@ -203,20 +204,26 @@ source_set("platform_wtf") {
     "text/TextCodecASCIIFastPath.h",
     "text/TextCodecICU.cpp",
     "text/TextCodecICU.h",
+    "text/TextCodecICU.h",
     "text/TextCodecLatin1.cpp",
     "text/TextCodecLatin1.h",
+    "text/TextCodecLatin1.h",
     "text/TextCodecReplacement.cpp",
     "text/TextCodecReplacement.h",
     "text/TextCodecUTF16.cpp",
     "text/TextCodecUTF16.h",
+    "text/TextCodecUTF16.h",
     "text/TextCodecUTF8.cpp",
     "text/TextCodecUTF8.h",
     "text/TextCodecUserDefined.cpp",
     "text/TextCodecUserDefined.h",
+    "text/TextCodecUserDefined.h",
     "text/TextEncoding.cpp",
     "text/TextEncoding.h",
+    "text/TextEncoding.h",
     "text/TextEncodingRegistry.cpp",
     "text/TextEncodingRegistry.h",
+    "text/TextEncodingRegistry.h",
     "text/TextPosition.cpp",
     "text/TextPosition.h",
     "text/UTF8.cpp",