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/svg/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//third_party/WebKit/Source/core/core.gni")
 
 blink_core_sources("svg") {
   # Split into multiple static libraries on Windows official builds, where we
   # run into a 2GB max size limit.
   if (is_win && is_official_build) {
     split_count = 5
   } else {
     split_count = 1
   }
 
   sources = [
     "ColorDistance.cpp",
     "ColorDistance.h",
     "GradientAttributes.h",
     "LinearGradientAttributes.h",
     "PatternAttributes.h",
     "RadialGradientAttributes.h",
     "SVGAElement.cpp",
     "SVGAElement.h",
     "SVGAngle.cpp",
+    "SVGAngle.h",
     "SVGAngleTearOff.cpp",
+    "SVGAngleTearOff.h",
     "SVGAnimateElement.cpp",
     "SVGAnimateElement.h",
     "SVGAnimateMotionElement.cpp",
     "SVGAnimateMotionElement.h",
     "SVGAnimateTransformElement.cpp",
     "SVGAnimateTransformElement.h",
     "SVGAnimatedAngle.cpp",
+    "SVGAnimatedAngle.h",
     "SVGAnimatedColor.cpp",
+    "SVGAnimatedColor.h",
     "SVGAnimatedEnumerationBase.cpp",
+    "SVGAnimatedEnumerationBase.h",
     "SVGAnimatedHref.cpp",
     "SVGAnimatedHref.h",
     "SVGAnimatedInteger.cpp",
+    "SVGAnimatedInteger.h",
     "SVGAnimatedIntegerOptionalInteger.cpp",
+    "SVGAnimatedIntegerOptionalInteger.h",
     "SVGAnimatedLength.cpp",
+    "SVGAnimatedLength.h",
     "SVGAnimatedNumber.cpp",
+    "SVGAnimatedNumber.h",
     "SVGAnimatedNumberOptionalNumber.cpp",
+    "SVGAnimatedNumberOptionalNumber.h",
     "SVGAnimatedPath.cpp",
+    "SVGAnimatedPath.h",
     "SVGAnimatedString.cpp",
     "SVGAnimatedString.h",
     "SVGAnimationElement.cpp",
     "SVGAnimationElement.h",
     "SVGBoolean.cpp",
     "SVGBoolean.h",
     "SVGCircleElement.cpp",
     "SVGCircleElement.h",
     "SVGClipPathElement.cpp",
     "SVGClipPathElement.h",
     "SVGComponentTransferFunctionElement.cpp",
     "SVGComponentTransferFunctionElement.h",
     "SVGDefsElement.cpp",
     "SVGDefsElement.h",
     "SVGDescElement.cpp",
     "SVGDescElement.h",
     "SVGDiscardElement.cpp",
     "SVGDiscardElement.h",
     "SVGDocumentExtensions.cpp",
+    "SVGDocumentExtensions.h",
     "SVGElement.cpp",
     "SVGElement.h",
     "SVGElementProxy.cpp",
     "SVGElementProxy.h",
     "SVGElementRareData.cpp",
     "SVGElementRareData.h",
     "SVGEllipseElement.cpp",
     "SVGEllipseElement.h",
     "SVGEnumeration.cpp",
+    "SVGEnumeration.h",
     "SVGFEBlendElement.cpp",
     "SVGFEBlendElement.h",
     "SVGFEColorMatrixElement.cpp",
     "SVGFEColorMatrixElement.h",
     "SVGFEComponentTransferElement.cpp",
     "SVGFEComponentTransferElement.h",
     "SVGFECompositeElement.cpp",
     "SVGFECompositeElement.h",
     "SVGFEConvolveMatrixElement.cpp",
     "SVGFEConvolveMatrixElement.h",
@@ skipping 57 matching lines @@
     "SVGGraphicsElement.h",
     "SVGImageElement.cpp",
     "SVGImageElement.h",
     "SVGImageLoader.cpp",
     "SVGImageLoader.h",
     "SVGInteger.cpp",
     "SVGInteger.h",
     "SVGIntegerOptionalInteger.cpp",
     "SVGIntegerOptionalInteger.h",
     "SVGLength.cpp",
+    "SVGLength.h",
     "SVGLengthContext.cpp",
+    "SVGLengthContext.h",
     "SVGLengthList.cpp",
+    "SVGLengthList.h",
     "SVGLengthTearOff.cpp",
+    "SVGLengthTearOff.h",
     "SVGLineElement.cpp",
     "SVGLineElement.h",
     "SVGLinearGradientElement.cpp",
     "SVGLinearGradientElement.h",
     "SVGMPathElement.cpp",
     "SVGMPathElement.h",
     "SVGMarkerElement.cpp",
     "SVGMarkerElement.h",
     "SVGMaskElement.cpp",
     "SVGMaskElement.h",
@@ skipping 46 matching lines @@
     "SVGPointList.h",
     "SVGPointTearOff.cpp",
     "SVGPointTearOff.h",
     "SVGPolyElement.cpp",
     "SVGPolyElement.h",
     "SVGPolygonElement.cpp",
     "SVGPolygonElement.h",
     "SVGPolylineElement.cpp",
     "SVGPolylineElement.h",
     "SVGPreserveAspectRatio.cpp",
+    "SVGPreserveAspectRatio.h",
     "SVGPreserveAspectRatioTearOff.cpp",
+    "SVGPreserveAspectRatioTearOff.h",
     "SVGRadialGradientElement.cpp",
     "SVGRadialGradientElement.h",
     "SVGRect.cpp",
     "SVGRect.h",
     "SVGRectElement.cpp",
     "SVGRectElement.h",
     "SVGRectTearOff.cpp",
     "SVGRectTearOff.h",
     "SVGResourceClient.h",
     "SVGSVGElement.cpp",
@@ skipping 26 matching lines @@
     "SVGTextContentElement.h",
     "SVGTextElement.cpp",
     "SVGTextElement.h",
     "SVGTextPathElement.cpp",
     "SVGTextPathElement.h",
     "SVGTextPositioningElement.cpp",
     "SVGTextPositioningElement.h",
     "SVGTitleElement.cpp",
     "SVGTitleElement.h",
     "SVGTransform.cpp",
+    "SVGTransform.h",
     "SVGTransformDistance.cpp",
     "SVGTransformDistance.h",
     "SVGTransformList.cpp",
+    "SVGTransformList.h",
     "SVGTransformListTearOff.cpp",
+    "SVGTransformListTearOff.h",
     "SVGTransformTearOff.cpp",
+    "SVGTransformTearOff.h",
     "SVGTreeScopeResources.cpp",
     "SVGTreeScopeResources.h",
     "SVGURIReference.cpp",
     "SVGURIReference.h",
     "SVGUnitTypes.cpp",
     "SVGUnitTypes.h",
     "SVGUnknownElement.cpp",
     "SVGUnknownElement.h",
     "SVGUseElement.cpp",
     "SVGUseElement.h",
     "SVGViewElement.cpp",
     "SVGViewElement.h",
     "SVGViewSpec.cpp",
     "SVGViewSpec.h",
     "SVGZoomAndPan.cpp",
     "SVGZoomAndPan.h",
     "animation/SMILTime.cpp",
+    "animation/SMILTime.h",
     "animation/SMILTimeContainer.cpp",
     "animation/SMILTimeContainer.h",
     "animation/SVGSMILElement.cpp",
+    "animation/SVGSMILElement.h",
     "graphics/SVGImage.cpp",
     "graphics/SVGImage.h",
     "graphics/SVGImageChromeClient.cpp",
     "graphics/SVGImageChromeClient.h",
     "graphics/SVGImageForContainer.cpp",
     "graphics/SVGImageForContainer.h",
     "graphics/filters/SVGFEImage.cpp",
     "graphics/filters/SVGFEImage.h",
     "graphics/filters/SVGFilterBuilder.cpp",
     "graphics/filters/SVGFilterBuilder.h",
     "properties/SVGAnimatedProperty.cpp",
+    "properties/SVGAnimatedProperty.h",
     "properties/SVGPropertyTearOff.cpp",
+    "properties/SVGPropertyTearOff.h",
   ]
 
   configs += [
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 }