linux: Pass subpixel positioning setting to WebKit.

This makes us configure renderers appropriately based on
--enable-text-subpixel-positioning.  It also updates
SandboxIPCProcess to pass the flag through so the results
returned by its calls to WebFontInfo::renderStyleForStrike()
will reflect the setting.

BUG=125066
TEST=manual: both regular and web fonts within the renderer use subpixel positioning when --enable-text-subpixel-positioning is set


Review URL: https://chromiumcodereview.appspot.com/10540038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@141246 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 42 insertions, 13 deletions

diff --git a/chrome/browser/renderer_preferences_util.cc b/chrome/browser/renderer_preferences_util.cc
index 96cbbc4..7c66eb2 100644
--- a/chrome/browser/renderer_preferences_util.cc
+++ b/chrome/browser/renderer_preferences_util.cc
@@ -12,6 +12,9 @@
 #if defined(TOOLKIT_GTK)
 #include "chrome/browser/ui/gtk/gtk_theme_service.h"
 #include "chrome/browser/ui/gtk/gtk_util.h"
+#elif defined(USE_ASH)
+#include "base/command_line.h"
+#include "ui/base/ui_base_switches.h"
 #endif
 
 namespace renderer_preferences_util {
@@ -36,6 +39,12 @@ void UpdateFromSystemSettings(
   prefs->inactive_selection_fg_color =
       theme_service->get_inactive_selection_fg_color();
 #elif defined(USE_ASH)
+  // TODO(derat): This code and GetCairoFontOptions() from ui/gfx/pango_util.cc
+  // should get their settings from the same place.
+  prefs->use_subpixel_positioning =
+      CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableTextSubpixelPositioning);
+
   // This color is 0x544d90fe modulated with 0xffffff.
   prefs->active_selection_bg_color = SkColorSetRGB(0xCB, 0xE4, 0xFA);
   prefs->active_selection_fg_color = SK_ColorBLACK;
diff --git a/content/browser/renderer_host/render_sandbox_host_linux.cc b/content/browser/renderer_host/render_sandbox_host_linux.cc
index 8681ddd..3685a89 100644
--- a/content/browser/renderer_host/render_sandbox_host_linux.cc
+++ b/content/browser/renderer_host/render_sandbox_host_linux.cc
@@ -34,6 +34,7 @@
 #include "third_party/npapi/bindings/npapi_extensions.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebKit.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/linux/WebFontInfo.h"
+#include "ui/base/ui_base_switches.h"
 
 using WebKit::WebCString;
 using WebKit::WebFontInfo;
@@ -62,6 +63,12 @@ class SandboxIPCProcess  {
       sandbox_cmd_.push_back(sandbox_cmd);
       sandbox_cmd_.push_back(base::kFindInodeSwitch);
     }
+
+    // FontConfig doesn't provide a standard property to control subpixel
+    // positioning, so we pass a UI flag through to WebKit.
+    WebFontInfo::setSubpixelPositioning(
+        CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kEnableTextSubpixelPositioning));
   }
 
   ~SandboxIPCProcess();
@@ -300,7 +307,8 @@ class SandboxIPCProcess  {
     reply.WriteInt(style.useHinting);
     reply.WriteInt(style.hintStyle);
     reply.WriteInt(style.useAntiAlias);
-    reply.WriteInt(style.useSubpixel);
+    reply.WriteInt(style.useSubpixelRendering);
+    reply.WriteInt(style.useSubpixelPositioning);
 
     SendRendererReply(fds, reply, -1);
   }
diff --git a/content/common/child_process_sandbox_support_impl_linux.cc b/content/common/child_process_sandbox_support_impl_linux.cc
index 5a07986..9294e7b 100644
--- a/content/common/child_process_sandbox_support_impl_linux.cc
+++ b/content/common/child_process_sandbox_support_impl_linux.cc
@@ -65,19 +65,22 @@ void GetRenderStyleForStrike(const char* family, int sizeAndStyle,
 
   Pickle reply(reinterpret_cast<char*>(buf), n);
   PickleIterator pickle_iter(reply);
-  int useBitmaps, useAutoHint, useHinting, hintStyle, useAntiAlias, useSubpixel;
+  int useBitmaps, useAutoHint, useHinting, hintStyle, useAntiAlias;
+  int useSubpixelRendering, useSubpixelPositioning;
   if (reply.ReadInt(&pickle_iter, &useBitmaps) &&
       reply.ReadInt(&pickle_iter, &useAutoHint) &&
       reply.ReadInt(&pickle_iter, &useHinting) &&
       reply.ReadInt(&pickle_iter, &hintStyle) &&
       reply.ReadInt(&pickle_iter, &useAntiAlias) &&
-      reply.ReadInt(&pickle_iter, &useSubpixel)) {
+      reply.ReadInt(&pickle_iter, &useSubpixelRendering) &&
+      reply.ReadInt(&pickle_iter, &useSubpixelPositioning)) {
     out->useBitmaps = useBitmaps;
     out->useAutoHint = useAutoHint;
     out->useHinting = useHinting;
     out->hintStyle = hintStyle;
     out->useAntiAlias = useAntiAlias;
-    out->useSubpixel = useSubpixel;
+    out->useSubpixelRendering = useSubpixelRendering;
+    out->useSubpixelPositioning = useSubpixelPositioning;
   }
 }
 
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index 09c6cf3..0d43b11 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -296,6 +296,7 @@ IPC_STRUCT_TRAITS_BEGIN(content::RendererPreferences)
   IPC_STRUCT_TRAITS_MEMBER(should_antialias_text)
   IPC_STRUCT_TRAITS_MEMBER(hinting)
   IPC_STRUCT_TRAITS_MEMBER(subpixel_rendering)
+  IPC_STRUCT_TRAITS_MEMBER(use_subpixel_positioning)
   IPC_STRUCT_TRAITS_MEMBER(focus_ring_color)
   IPC_STRUCT_TRAITS_MEMBER(thumb_active_color)
   IPC_STRUCT_TRAITS_MEMBER(thumb_inactive_color)
diff --git a/content/public/common/renderer_preferences.cc b/content/public/common/renderer_preferences.cc
index 8d6dc3c..ddb4c11 100644
--- a/content/public/common/renderer_preferences.cc
+++ b/content/public/common/renderer_preferences.cc
@@ -12,6 +12,7 @@ RendererPreferences::RendererPreferences()
       hinting(RENDERER_PREFERENCES_HINTING_SYSTEM_DEFAULT),
       subpixel_rendering(
           RENDERER_PREFERENCES_SUBPIXEL_RENDERING_SYSTEM_DEFAULT),
+      use_subpixel_positioning(false),
       focus_ring_color(0),
       thumb_active_color(0),
       thumb_inactive_color(0),
diff --git a/content/public/common/renderer_preferences.h b/content/public/common/renderer_preferences.h
index b745d09..ac7e58c 100644
--- a/content/public/common/renderer_preferences.h
+++ b/content/public/common/renderer_preferences.h
@@ -54,6 +54,10 @@ struct CONTENT_EXPORT RendererPreferences {
   // Currently only used by Linux.
   RendererPreferencesSubpixelRenderingEnum subpixel_rendering;
 
+  // Whether subpixel positioning should be used, permitting fractional X
+  // positions for glyphs.  Currently only used by Linux.
+  bool use_subpixel_positioning;
+
   // The color of the focus ring. Currently only used on Linux.
   SkColor focus_ring_color;
 
diff --git a/content/renderer/render_view_linux.cc b/content/renderer/render_view_linux.cc
index e48ba8c..ca35529 100644
--- a/content/renderer/render_view_linux.cc
+++ b/content/renderer/render_view_linux.cc
@@ -1,12 +1,14 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
 #include "content/renderer/render_view_impl.h"
 
 #include "content/public/common/renderer_preferences.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/linux/WebFontInfo.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/linux/WebFontRendering.h"
 
+using WebKit::WebFontInfo;
 using WebKit::WebFontRendering;
 
 static SkPaint::Hinting RendererPreferencesToSkiaHinting(
@@ -86,7 +88,7 @@ static bool RendererPreferencesToAntiAliasFlag(
   return prefs.should_antialias_text;
 }
 
-static bool RendererPreferencesToSubpixelGlyphsFlag(
+static bool RendererPreferencesToSubpixelRenderingFlag(
     const content::RendererPreferences& prefs) {
   if (prefs.subpixel_rendering !=
         content::RENDERER_PREFERENCES_SUBPIXEL_RENDERING_SYSTEM_DEFAULT &&
@@ -94,18 +96,19 @@ static bool RendererPreferencesToSubpixelGlyphsFlag(
         content::RENDERER_PREFERENCES_SUBPIXEL_RENDERING_NONE) {
     return true;
   }
-
   return false;
 }
 
 void RenderViewImpl::UpdateFontRenderingFromRendererPrefs() {
   const content::RendererPreferences& prefs = renderer_preferences_;
   WebFontRendering::setHinting(RendererPreferencesToSkiaHinting(prefs));
-  WebFontRendering::setLCDOrder(RendererPreferencesToSkiaLCDOrder(
-      prefs.subpixel_rendering));
-  WebFontRendering::setLCDOrientation(RendererPreferencesToSkiaLCDOrientation(
-      prefs.subpixel_rendering));
+  WebFontRendering::setLCDOrder(
+      RendererPreferencesToSkiaLCDOrder(prefs.subpixel_rendering));
+  WebFontRendering::setLCDOrientation(
+      RendererPreferencesToSkiaLCDOrientation(prefs.subpixel_rendering));
   WebFontRendering::setAntiAlias(RendererPreferencesToAntiAliasFlag(prefs));
-  WebFontRendering::setSubpixelGlyphs(RendererPreferencesToSubpixelGlyphsFlag(
-      prefs));
+  WebFontRendering::setSubpixelRendering(
+      RendererPreferencesToSubpixelRenderingFlag(prefs));
+  WebFontRendering::setSubpixelPositioning(prefs.use_subpixel_positioning);
+  WebFontInfo::setSubpixelPositioning(prefs.use_subpixel_positioning);
 }