improvements of the FPS counter in the HUDLayer

cc/font_atlas.cc

 // Copyright 2012 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 "cc/font_atlas.h"
 
 #include <vector>
 
@@ skipping 42 matching lines @@
     for (unsigned i = 0; i < textLine.length(); ++i) {
         // If the ASCII code is out of bounds, then index 0 is used, which is just a plain rectangle glyph.
         int asciiIndex = (textLine[i] < 128) ? textLine[i] : 0;
         IntRect glyphBounds = m_asciiToRectTable[asciiIndex];
         SkIRect source = SkIRect::MakeXYWH(glyphBounds.x(), glyphBounds.y(), glyphBounds.width(), glyphBounds.height());
         canvas->drawBitmapRect(m_atlas, &source, SkRect::MakeXYWH(position.x(), position.y(), glyphBounds.width(), glyphBounds.height()), &paint);
         position.set_x(position.x() + glyphBounds.width());
     }
 }
 
+IntSize FontAtlas::textSize(const std::string& text)
+{
+    int maxWidth = 0;
+    std::vector<std::string> lines;
+    base::SplitString(text, '\n', &lines);
+
+    for (size_t i = 0; i < lines.size(); ++i) {
+        int lineWidth = 0;
+        for (size_t j = 0; j < lines[i].size(); ++j) {
+            int asciiIndex = (lines[i][j] < 128) ? lines[i][j] : 0;
+            lineWidth += m_asciiToRectTable[asciiIndex].width();
+        }
+        if (lineWidth > maxWidth)
+            maxWidth = lineWidth;
+    }
+
+    return IntSize(maxWidth, m_fontHeight * lines.size());
+}
+
 void FontAtlas::drawDebugAtlas(SkCanvas* canvas, const gfx::Point& destPosition) const
 {
     DCHECK(Proxy::isImplThread());
 
     SkIRect source = SkIRect::MakeWH(m_atlas.width(), m_atlas.height());
     canvas->drawBitmapRect(m_atlas, &source, SkRect::MakeXYWH(destPosition.x(), destPosition.y(), m_atlas.width(), m_atlas.height()));
 }
 
 } // namespace cc