Prefer to forward-declare GraphicsContext in headers.

Source/core/rendering/InlineTextBox.h

Index: Source/core/rendering/InlineTextBox.h
diff --git a/Source/core/rendering/InlineTextBox.h b/Source/core/rendering/InlineTextBox.h
index e2db766e70651e7a02db6eeb35644edb2025e861..cb5db91480a8bf47035945634c6cf3d835005f3c 100644
--- a/Source/core/rendering/InlineTextBox.h
+++ b/Source/core/rendering/InlineTextBox.h
@@ -25,7 +25,6 @@
 
 #include "core/rendering/InlineBox.h"
 #include "core/rendering/RenderText.h" // so textRenderer() can be inline
-#include "platform/graphics/GraphicsContext.h"
 #include "platform/text/TextRun.h"
 #include "wtf/Forward.h"
 
@@ -33,6 +32,7 @@ namespace WebCore {
 
 struct CompositionUnderline;
 class DocumentMarker;
+class GraphicsContext;
 
 const unsigned short cNoTruncation = USHRT_MAX;
 const unsigned short cFullTruncation = USHRT_MAX - 1;