Add font_scale_factor_quirk pref.

content/renderer/web_preferences.cc

 // Copyright 2013 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/public/renderer/web_preferences.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/web/WebKit.h"
 #include "third_party/WebKit/public/web/WebNetworkStateNotifier.h"
 #include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
 #include "third_party/WebKit/public/web/WebSettings.h"
 #include "third_party/WebKit/public/web/WebView.h"
 #include "third_party/icu/source/common/unicode/uchar.h"
 #include "third_party/icu/source/common/unicode/uscript.h"
 #include "webkit/common/webpreferences.h"
 
+#if defined(OS_ANDROID)
+#include "ui/gfx/android/device_display_info.h"
+#endif
+
 using WebKit::WebNetworkStateNotifier;
 using WebKit::WebRuntimeFeatures;
 using WebKit::WebSettings;
 using WebKit::WebString;
 using WebKit::WebURL;
 using WebKit::WebView;
 
 namespace content {
 
 namespace {
@@ skipping 73 matching lines @@
        it != map.end();
        ++it) {
     int32 script = u_getPropertyValueEnum(UCHAR_SCRIPT, (it->first).c_str());
     if (script >= 0 && script < USCRIPT_CODE_LIMIT) {
       UScriptCode code = static_cast<UScriptCode>(script);
       (*setter)(settings, it->second, GetScriptForWebSettings(code));
     }
   }
 }
 
+#if defined(OS_ANDROID)
+
+const float kMinFSM = 1.05f;
+const int kWidthForMinFSM = 320;
+const float kMaxFSM = 1.3f;
+const int kWidthForMaxFSM = 800;
+
+float GetFontScaleMultiplier(const WebPreferences& prefs) {
+  if (prefs.font_scale_factor_quirk) {
+    // The value of font_scale_factor passed by Chrome for Android already
+    // includes the multiplier.
+    return 1.0;
+  }
+  gfx::DeviceDisplayInfo info;
+  int minWidth = info.GetSmallestDIPWidth();

[jamesr, 2013/10/21 17:58:33]

we shouldn't be doing logic like this here in the renderer - set up the value in
the browser process

+
+  if (minWidth <= kWidthForMinFSM)
+    return kMinFSM;
+  if (minWidth >= kWidthForMaxFSM)
+    return kMaxFSM;
+
+  // The font scale multiplier varies linearly between kMinFSM and kMaxFSM.
+  float ratio = static_cast<float>(minWidth - kWidthForMinFSM) /
+      (kWidthForMaxFSM - kWidthForMinFSM);
+  return ratio * (kMaxFSM - kMinFSM) + kMinFSM;
+}
+
+#endif  // defined(OS_ANDROID)
+
 }  // namespace
 
 void ApplyWebPreferences(const WebPreferences& prefs, WebView* web_view) {
   WebSettings* settings = web_view->settings();
   ApplyFontsFromMap(prefs.standard_font_family_map,
                     setStandardFontFamilyWrapper, settings);
   ApplyFontsFromMap(prefs.fixed_font_family_map,
                     setFixedFontFamilyWrapper, settings);
   ApplyFontsFromMap(prefs.serif_font_family_map,
                     setSerifFontFamilyWrapper, settings);
@@ skipping 195 matching lines @@
 
   settings->setSmartInsertDeleteEnabled(prefs.smart_insert_delete_enabled);
 
   settings->setSpatialNavigationEnabled(prefs.spatial_navigation_enabled);
 
   settings->setSelectionIncludesAltImageText(true);
 
 #if defined(OS_ANDROID)
   settings->setAllowCustomScrollbarInMainFrame(false);
   settings->setTextAutosizingEnabled(prefs.text_autosizing_enabled);
-  settings->setTextAutosizingFontScaleFactor(prefs.font_scale_factor);
+  settings->setTextAutosizingFontScaleFactor(
+      prefs.font_scale_factor * GetFontScaleMultiplier(prefs));
   web_view->setIgnoreViewportTagScaleLimits(prefs.force_enable_zoom);
   settings->setAutoZoomFocusedNodeToLegibleScale(true);
   settings->setDoubleTapToZoomEnabled(prefs.double_tap_to_zoom_enabled);
   settings->setMediaPlaybackRequiresUserGesture(
       prefs.user_gesture_required_for_media_playback);
   settings->setMediaFullscreenRequiresUserGesture(
       prefs.user_gesture_required_for_media_fullscreen);
   settings->setDefaultVideoPosterURL(
         ASCIIToUTF16(prefs.default_video_poster_url.spec()));
   settings->setSupportDeprecatedTargetDensityDPI(
@@ skipping 18 matching lines @@
   settings->setPinchVirtualViewportEnabled(
       prefs.pinch_virtual_viewport_enabled);
 
   settings->setPinchOverlayScrollbarThickness(
       prefs.pinch_overlay_scrollbar_thickness);
   settings->setUseSolidColorScrollbars(prefs.use_solid_color_scrollbars);
   settings->setCompositorTouchHitTesting(prefs.compositor_touch_hit_testing);
 }
 
 }  // namespace content