[Linux] Enable subpixel text on high-dpi regardless of hinting

Source/platform/graphics/GraphicsContext.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 105 matching lines @@
     , m_paintStateStack()
     , m_paintStateIndex(0)
     , m_pendingCanvasSave(false)
     , m_annotationMode(0)
 #if ENABLE(ASSERT)
     , m_annotationCount(0)
     , m_layerCount(0)
     , m_disableDestructionChecks(false)
 #endif
     , m_disabledState(disableContextOrPainting)
+    , m_deviceScaleFactor(1.0f)
     , m_trackOpaqueRegion(false)
     , m_trackTextRegion(false)
-    , m_useHighResMarker(false)
     , m_updatingControlTints(false)
     , m_accelerated(false)
     , m_isCertainlyOpaque(true)
     , m_printing(false)
     , m_antialiasHairlineImages(false)
 {
     if (!canvas)
         m_disabledState |= PaintingDisabled;
 
     // FIXME: Do some tests to determine how many states are typically used, and allocate
@@ skipping 579 matching lines @@
 
     if (m_trackOpaqueRegion)
         m_opaqueRegion.didDrawPoints(this, SkCanvas::kLines_PointMode, 2, pts, paint);
 }
 
 void GraphicsContext::drawLineForDocumentMarker(const FloatPoint& pt, float width, DocumentMarkerLineStyle style)
 {
     if (contextDisabled())
         return;
 
-    int deviceScaleFactor = m_useHighResMarker ? 2 : 1;
+    // Use 2x resources for a device scale factor of 1.5 or above.
+    int deviceScaleFactor = m_deviceScaleFactor > 1.5f ? 2 : 1;
 
     // Create the pattern we'll use to draw the underline.
     int index = style == DocumentMarkerGrammarLineStyle ? 1 : 0;
     static SkBitmap* misspellBitmap1x[2] = { 0, 0 };
     static SkBitmap* misspellBitmap2x[2] = { 0, 0 };
     SkBitmap** misspellBitmap = deviceScaleFactor == 2 ? misspellBitmap2x : misspellBitmap1x;
     if (!misspellBitmap[index]) {
 #if OS(MACOSX)
         // Match the artwork used by the Mac.
         const int rowPixels = 4 * deviceScaleFactor;
@@ skipping 1087 matching lines @@
 
 void GraphicsContext::didDrawTextInRect(const SkRect& textRect)
 {
     if (m_trackTextRegion) {
         TRACE_EVENT0("skia", "GraphicsContext::didDrawTextInRect");
         m_textRegion.join(textRect);
     }
 }
 
 }