Use SkPaint::getFontBounds() for text bounding boxes in pictures.

src/core/SkPaint.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPaint.h"
 #include "SkAnnotation.h"
 #include "SkAutoKern.h"
@@ skipping 1220 matching lines @@
         matrix.postTranslate(pos[i].fX - prevPos.fX, pos[i].fY - prevPos.fY);
         if (iterPath) {
             path->addPath(*iterPath, matrix);
         }
         prevPos = pos[i];
         i++;
     }
 }
 
 SkRect SkPaint::getFontBounds() const {
+    // This approach can be a little over 1% too narrow when using GDI,
+    // so we compensate by scaling the x-axis another 2%.
+    SkScalar xScale = fTextScaleX * 1.02f;
+
     SkMatrix m;
-    m.setScale(fTextSize * fTextScaleX, fTextSize);
+    m.setScale(fTextSize * xScale, fTextSize);
     m.postSkew(fTextSkewX, 0);
 
     SkTypeface* typeface = this->getTypeface();
     if (NULL == typeface) {
         typeface = SkTypeface::GetDefaultTypeface();
     }
 
     SkRect bounds;
     m.mapRect(&bounds, typeface->getBounds());
     return bounds;
@@ skipping 1131 matching lines @@
 }
 
 uint32_t SkPaint::getHash() const {
     // We're going to hash 10 pointers and 7 32-bit values, finishing up with fBitfields,
     // so fBitfields should be 10 pointers and 6 32-bit values from the start.
     SK_COMPILE_ASSERT(offsetof(SkPaint, fBitfields) == 10 * sizeof(void*) + 6 * sizeof(uint32_t),
                       SkPaint_notPackedTightly);
     return SkChecksum::Murmur3(reinterpret_cast<const uint32_t*>(this),
                                offsetof(SkPaint, fBitfields) + sizeof(fBitfields));
 }