Avoid rounding down viewport dimensions in Media Queries

third_party/WebKit/Source/core/css/MediaValues.cpp

 // Copyright 2014 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 "config.h"
 #include "core/css/MediaValues.h"
 
 #include "core/css/CSSHelper.h"
 #include "core/css/MediaValuesCached.h"
 #include "core/css/MediaValuesDynamic.h"
@@ skipping 14 matching lines @@
 
 namespace blink {
 
 PassRefPtrWillBeRawPtr<MediaValues> MediaValues::createDynamicIfFrameExists(LocalFrame* frame)
 {
     if (frame)
         return MediaValuesDynamic::create(frame);
     return MediaValuesCached::create();
 }
 
-int MediaValues::calculateViewportWidth(LocalFrame* frame) const
+double MediaValues::calculateViewportWidth(LocalFrame* frame) const
 {
     ASSERT(frame && frame->view() && frame->document());
     int viewportWidth = frame->view()->layoutSize(IncludeScrollbars).width();
-    return adjustForAbsoluteZoom(viewportWidth, frame->document()->layoutView());
+    return adjustDoubleForAbsoluteZoom(viewportWidth, *frame->document()->layoutView());
 }
 
-int MediaValues::calculateViewportHeight(LocalFrame* frame) const
+double MediaValues::calculateViewportHeight(LocalFrame* frame) const
 {
     ASSERT(frame && frame->view() && frame->document());
     int viewportHeight = frame->view()->layoutSize(IncludeScrollbars).height();
-    return adjustForAbsoluteZoom(viewportHeight, frame->document()->layoutView());
+    return adjustDoubleForAbsoluteZoom(viewportHeight, *frame->document()->layoutView());
 }
 
 int MediaValues::calculateDeviceWidth(LocalFrame* frame) const
 {
     ASSERT(frame && frame->view() && frame->settings() && frame->host());
     int deviceWidth = frame->host()->chromeClient().screenInfo().rect.width;
     if (frame->settings()->reportScreenSizeInPhysicalPixelsQuirk())
         deviceWidth = lroundf(deviceWidth * frame->host()->deviceScaleFactor());
     return deviceWidth;
 }
@@ skipping 89 matching lines @@
     ASSERT(frame && frame->settings());
     return frame->settings()->primaryHoverType();
 }
 
 int MediaValues::calculateAvailableHoverTypes(LocalFrame* frame) const
 {
     ASSERT(frame && frame->settings());
     return frame->settings()->availableHoverTypes();
 }
 
-bool MediaValues::computeLengthImpl(double value, CSSPrimitiveValue::UnitType type, unsigned defaultFontSize, unsigned viewportWidth, unsigned viewportHeight, double& result)
+bool MediaValues::computeLengthImpl(double value, CSSPrimitiveValue::UnitType type, unsigned defaultFontSize, double viewportWidth, double viewportHeight, double& result)
 {
     // The logic in this function is duplicated from CSSToLengthConversionData::zoomedComputedPixels()
     // because MediaValues::computeLength() needs nearly identical logic, but we haven't found a way to make
     // CSSToLengthConversionData::zoomedComputedPixels() more generic (to solve both cases) without hurting performance.
 
     // FIXME - Unite the logic here with CSSToLengthConversionData in a performant way.
     double factor = 0;
     switch (type) {
     case CSSPrimitiveValue::UnitType::Ems:
     case CSSPrimitiveValue::UnitType::Rems:
@@ skipping 51 matching lines @@
 }
 
 LocalFrame* MediaValues::frameFrom(Document& document)
 {
     Document* executingDocument = document.importsController() ? document.importsController()->master() : &document;
     ASSERT(executingDocument);
     return executingDocument->frame();
 }
 
 } // namespace