[svg2] Make 'x' and 'y' presentation attributes

Source/core/svg/SVGLengthContext.cpp

Index: Source/core/svg/SVGLengthContext.cpp
diff --git a/Source/core/svg/SVGLengthContext.cpp b/Source/core/svg/SVGLengthContext.cpp
index 9c1a4d15c19902e297c787185e7235ac2ac2bef3..e559e889822dcc24a026de6f2cababcf0070044d 100644
--- a/Source/core/svg/SVGLengthContext.cpp
+++ b/Source/core/svg/SVGLengthContext.cpp
@@ -32,6 +32,7 @@
 #include "core/rendering/svg/RenderSVGRoot.h"
 #include "core/rendering/svg/RenderSVGViewportContainer.h"
 #include "core/svg/SVGSVGElement.h"
+#include "platform/LengthFunctions.h"
 #include "platform/fonts/FontMetrics.h"
 
 namespace blink {
@@ -91,6 +92,27 @@ float SVGLengthContext::resolveLength(const SVGElement* context, SVGUnitTypes::S
     return x->valueAsPercentage();
 }
 
+float SVGLengthContext::valueForLength(const Length& length, SVGLengthMode mode)
+{
+    if (length.isPercent())
+        return convertValueFromPercentageToUserUnits(length.value() / 100, mode, IGNORE_EXCEPTION);

[fs, 2015/02/04 13:24:53]

Move this after the 'auto' check, and then use the version of
convertValueFromPercentageToUserUnits that doesn't take an ExceptionState (but a
viewport-size).

[fs, 2015/02/04 13:24:53]

I'm sure bratell would want you to do the division last ;-)

[Erik Dahlström (inactive), 2015/02/05 16:09:02]

Done.

[Erik Dahlström (inactive), 2015/02/05 16:09:02]

Done.

+    if (length.isAuto())
+        return 0;
+
+    FloatSize viewportSize;
+    determineViewport(viewportSize);
+
+    switch (mode) {
+    case LengthModeWidth:

[fs, 2015/02/04 13:24:53]

(Given the amount of these switches this file/class now has, I wonder if it
wouldn't be nicer to factor these as:

static float factorForLengthMode(SVGLengthMode mode, const FloatSize&
viewportSize)
{
    switch (mode) {
    case LengthModeWidth:
        return viewportSize.width();
...
    }
}

...
return floatValueForLength(length, factorForLengthMode(...));

I'll see if I can whip something up for that...)

[Erik Dahlström (inactive), 2015/02/05 16:09:02]

Acknowledged.

+        return floatValueForLength(length, viewportSize.width());
+    case LengthModeHeight:
+        return floatValueForLength(length, viewportSize.height());
+    case LengthModeOther:
+        return floatValueForLength(length, sqrtf(viewportSize.diagonalLengthSquared() / 2));
+    };
+    return 0;
+}
+
 float SVGLengthContext::convertValueToUserUnits(float value, SVGLengthMode mode, SVGLengthType fromUnit, ExceptionState& exceptionState) const
 {
     switch (fromUnit) {