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

third_party/WebKit/Source/core/editing/BUILD.gn

Index: third_party/WebKit/Source/core/editing/BUILD.gn
diff --git a/third_party/WebKit/Source/core/editing/BUILD.gn b/third_party/WebKit/Source/core/editing/BUILD.gn
index 417c089f51d4594012b639f68a8e6b25de3e7ca3..2ee26051f23a5081f76f11d54bffded0c13c4570 100644
--- a/third_party/WebKit/Source/core/editing/BUILD.gn
+++ b/third_party/WebKit/Source/core/editing/BUILD.gn
@@ -20,6 +20,7 @@ blink_core_sources("editing") {
     "EditingStrategy.cpp",
     "EditingStrategy.h",
     "EditingStyle.cpp",
+    "EditingStyle.h",
     "EditingStyleUtilities.cpp",
     "EditingStyleUtilities.h",
     "EditingUtilities.cpp",
@@ -31,7 +32,9 @@ blink_core_sources("editing") {
     "FrameCaret.cpp",
     "FrameCaret.h",
     "FrameSelection.cpp",
+    "FrameSelection.h",
     "GranularityStrategy.cpp",
+    "GranularityStrategy.h",
     "InputMethodController.cpp",
     "InputMethodController.h",
     "PendingSelection.cpp",
@@ -64,8 +67,11 @@ blink_core_sources("editing") {
     "TextAffinity.cpp",
     "TextAffinity.h",
     "VisiblePosition.cpp",
+    "VisiblePosition.h",
     "VisibleSelection.cpp",
+    "VisibleSelection.h",
     "VisibleUnits.cpp",
+    "VisibleUnits.h",
     "commands/AppendNodeCommand.cpp",
     "commands/AppendNodeCommand.h",
     "commands/ApplyBlockElementCommand.cpp",
@@ -147,16 +153,21 @@ blink_core_sources("editing") {
     "commands/WrapContentsInDummySpanCommand.cpp",
     "commands/WrapContentsInDummySpanCommand.h",
     "iterators/BackwardsCharacterIterator.cpp",
+    "iterators/BackwardsCharacterIterator.h",
     "iterators/BackwardsTextBuffer.cpp",
     "iterators/BackwardsTextBuffer.h",
     "iterators/BitStack.cpp",
+    "iterators/BitStack.h",
     "iterators/CharacterIterator.cpp",
+    "iterators/CharacterIterator.h",
     "iterators/ForwardsTextBuffer.cpp",
     "iterators/ForwardsTextBuffer.h",
     "iterators/FullyClippedStateStack.cpp",
+    "iterators/FullyClippedStateStack.h",
     "iterators/SearchBuffer.cpp",
     "iterators/SearchBuffer.h",
     "iterators/SimplifiedBackwardsTextIterator.cpp",
+    "iterators/SimplifiedBackwardsTextIterator.h",
     "iterators/TextBufferBase.cpp",
     "iterators/TextBufferBase.h",
     "iterators/TextIterator.cpp",
@@ -168,6 +179,7 @@ blink_core_sources("editing") {
     "iterators/TextSearcherICU.cpp",
     "iterators/TextSearcherICU.h",
     "iterators/WordAwareIterator.cpp",
+    "iterators/WordAwareIterator.h",
     "markers/DocumentMarker.cpp",
     "markers/DocumentMarker.h",
     "markers/DocumentMarkerController.cpp",
@@ -275,6 +287,7 @@ source_set("unit_tests") {
     "state_machines/ForwardCodePointStateMachineTest.cpp",
     "state_machines/ForwardGraphemeBoundaryStateMachineTest.cpp",
     "state_machines/StateMachineTestUtil.cpp",
+    "state_machines/StateMachineTestUtil.h",
     "state_machines/StateMachineUtilTest.cpp",
   ]