Chromium for Mac cannot print surrogate pair in vertical writing mode

CoreText doesn't have vertical glyphs of surrogate pair characters, and
we draw broken glyphs. On Safari, wkGetVerticalGlyphsForCharacters
returns true, and we use the glyphs which is returned from the
SPI. However, according to the description of r149659,
WKGetVerticalGlyphsForCharacters() just returns false on
Chromium. Therefore, we cannot get vertical glyphs from Mac API/SPI.

To work around that, we should not use CoreText for surrogate pair
characters in vertical writing mode, but this always returns horizontal
glyphs.

BUG=337080

Review URL: https://codereview.chromium.org/145473002

git-svn-id: svn://svn.chromium.org/blink/trunk@166358 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/TestExpectations

@@ -494,6 +494,8 @@ crbug.com/254332 [ XP ] fast/forms/submit/submit-focus-by-mouse.html [ ImageOnly
 
 crbug.com/256506 [ Win7 Debug ] crypto/worker-random-values-limits.html [ Pass Crash ]
 
+crbug.com/337080 [ Mac Win Linux ] fast/text/vertical-surrogate-pair.html [ NeedsRebaseline ]
+
 crbug.com/244266 virtual/threaded/animations/animation-controller-drt-api.html [ Failure Pass ]
 
 crbug.com/265650 [ SnowLeopard Debug ] compositing/repaint/transform-style-change.html [ Pass ImageOnlyFailure ]

third_party/WebKit/LayoutTests/fast/text/vertical-surrogate-pair.html

+<style>
+    div { font-family: 'hiragino mincho pro'; font-size: 48px; }
+</style>
+<p>
+    These two glyphs should look the same:
+</p>
+<div>&#x20b9f;</div>
+<div style="-webkit-writing-mode: vertical-lr;">&#x20b9f;</div>

third_party/WebKit/LayoutTests/platform/mac/fast/text/vertical-surrogate-pair-expected.txt

+layer at (0,0) size 800x600
+  RenderView at (0,0) size 800x600
+layer at (0,0) size 800x600
+  RenderBlock {HTML} at (0,0) size 800x600
+    RenderBody {BODY} at (8,8) size 784x584
+      RenderBlock {P} at (0,0) size 784x18
+        RenderText {#text} at (0,0) size 253x18
+          text run at (0,0) width 253: "These two glyphs should look the same:"
+      RenderBlock {DIV} at (0,34) size 784x72
+        RenderText {#text} at (0,12) size 48x48
+          text run at (0,12) width 48: "\x{D842}\x{DF9F}"
+      RenderBlock {DIV} at (0,106) size 72x48
+        RenderText {#text} at (12,0) size 48x48
+          text run at (12,0) width 48: "\x{D842}\x{DF9F}"

third_party/WebKit/Source/platform/fonts/mac/GlyphPageTreeNodeMac.cpp

@@ -46,6 +46,16 @@ static bool shouldUseCoreText(UChar* buffer, unsigned bufferLength, const Simple
 {
     if (fontData->platformData().isCompositeFontReference())
         return true;
+
+    // CoreText doesn't have vertical glyphs of surrogate pair characters.
+    // Therefore, we should not use CoreText, but this always returns horizontal glyphs.
+    // FIXME: We should use vertical glyphs. https://code.google.com/p/chromium/issues/detail?id=340173
+    if (bufferLength >= 2 && U_IS_SURROGATE(buffer[0]) && fontData->hasVerticalGlyphs()) {
+        ASSERT(U_IS_SURROGATE_LEAD(buffer[0]));
+        ASSERT(U_IS_TRAIL(buffer[1]));
+        return false;
+    }
+
     if (fontData->platformData().widthVariant() != RegularWidth || fontData->hasVerticalGlyphs()) {
         // Ideographs don't have a vertical variant or width variants.
         for (unsigned i = 0; i < bufferLength; ++i) {