Expose InlineTextBoxes in the accessibility tree.

Source/core/rendering/InlineTextBox.cpp

Index: Source/core/rendering/InlineTextBox.cpp
diff --git a/Source/core/rendering/InlineTextBox.cpp b/Source/core/rendering/InlineTextBox.cpp
index 38f5c8f21ef51720071f1835ac5d6e9f438e013d..20e4204be347b2a5cf6518b17f720fcfa71c567b 100644
--- a/Source/core/rendering/InlineTextBox.cpp
+++ b/Source/core/rendering/InlineTextBox.cpp
@@ -35,6 +35,8 @@
 #include "core/platform/graphics/DrawLooper.h"
 #include "core/platform/graphics/FontCache.h"
 #include "core/platform/graphics/GraphicsContextStateSaver.h"
+#include "core/platform/graphics/WidthIterator.h"
+#include "core/rendering/AbstractInlineTextBox.h"
 #include "core/rendering/EllipsisBox.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/PaintInfo.h"
@@ -69,6 +71,8 @@ static const int misspellingLineThickness = 3;
 
 void InlineTextBox::destroy()
 {
+    AbstractInlineTextBox::willDestroy(this);
+
     if (!knownToHaveNoOverflow() && gTextBoxesWithOverflow)
         gTextBoxesWithOverflow->remove(this);
     InlineBox::destroy();
@@ -1474,6 +1478,27 @@ bool InlineTextBox::containsCaretOffset(int offset) const
     return true;
 }
 
+void InlineTextBox::characterWidths(Vector<float>& widths) const
+{
+    FontCachePurgePreventer fontCachePurgePreventer;
+
+    RenderText* textObj = textRenderer();
+    RenderStyle* styleToUse = textObj->style(isFirstLineStyle());
+    const Font& font = styleToUse->font();
+
+    TextRun textRun = constructTextRun(styleToUse, font);
+
+    GlyphBuffer glyphBuffer;
+    WidthIterator it(&font, textRun);
+    float lastWidth = 0;
+    widths.resize(m_len);
+    for (unsigned i = 0; i < m_len; i++) {
+        it.advance(i + 1, &glyphBuffer);

[aboxhall, 2013/10/17 22:27:55]

Could you do the advance() in the for statement, i.e.
for (unsigned i = 0; i < m_len && it.advance(i + 1, &glyphbuffer); i++) ?
Or is that less readable?

[dmazzoni, 2013/10/19 06:48:07]

I find it less readable because the iterator advance doesn't control the loop at
all - it doesn't return success/failure, etc.

+        widths[i] = it.m_runWidthSoFar - lastWidth;
+        lastWidth = it.m_runWidthSoFar;
+    }
+}
+
 TextRun InlineTextBox::constructTextRun(RenderStyle* style, const Font& font, StringBuilder* charactersWithHyphen) const
 {
     ASSERT(style);