[OSX] Turn on canvas_skia for OSX

ui/gfx/canvas_unittest_mac.mm

+// Copyright (c) 2011 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 "ui/gfx/canvas.h"
+
+#import <Cocoa/Cocoa.h>
+
+#include "base/strings/utf_string_conversions.h"
+#include "base/strings/sys_string_conversions.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/font.h"
+#include "ui/gfx/font_list.h"
+
+namespace gfx {
+
+namespace {
+
+// Mac-specific code for string size computations. This is a verbatim copy
+// of the old implementation that used to be in canvas_mac.mm.
+void CanvasMac_SizeStringInt(const base::string16& text,
+                             const FontList& font_list,
+                             int* width,
+                             int* height,
+                             int line_height,
+                             int flags) {
+  DLOG_IF(WARNING, line_height != 0) << "Line heights not implemented.";
+  DLOG_IF(WARNING, flags & Canvas::MULTI_LINE) << "Multi-line not implemented.";
+
+  NSFont* native_font = font_list.GetPrimaryFont().GetNativeFont();
+  NSString* ns_string = base::SysUTF16ToNSString(text);
+  NSDictionary* attributes =
+      [NSDictionary dictionaryWithObject:native_font
+                                  forKey:NSFontAttributeName];
+  NSSize string_size = [ns_string sizeWithAttributes:attributes];
+  *width = string_size.width;
+  *height = font_list.GetHeight();
+}
+
+}  // namespace
+
+class CanvasTestMac : public testing::Test {
+ protected:
+  // Compare the size returned by Canvas::SizeStringInt to the size generated
+  // by the platform-specific version in CanvasMac_SizeStringInt. Will generate
+  // expectation failure on any mismatch. Only works for single-line text
+  // without specified line height, since that is all the platform
+  // implementation supports.
+  void CompareSizes(const char* text) {
+    const int kReallyLargeNumber = 12345678;
+    FontList font_list(font_);
+    base::string16 text16 = base::UTF8ToUTF16(text);
+
+    int mac_width = kReallyLargeNumber;

[Alexei Svitkine (slow), 2013/09/13 02:06:37]

Just pass in 0 instead.

[groby-ooo-7-16, 2013/09/13 18:09:07]

I do this deliberately to catch cases where it accidentally returns the default
value. If you still want me to remove this, LMK
On 2013/09/13 02:06:37, Alexei Svitkine wrote:

+    int mac_height = kReallyLargeNumber;
+    CanvasMac_SizeStringInt(text16, font_list, &mac_width, &mac_height, 0, 0);
+
+    int canvas_width = kReallyLargeNumber;
+    int canvas_height = kReallyLargeNumber;
+    Canvas::SizeStringInt(
+        text16, font_list, &canvas_width, &canvas_height, 0, 0);
+
+    EXPECT_NE(kReallyLargeNumber, mac_width) << "no width for " << text;
+    EXPECT_NE(kReallyLargeNumber, mac_height) << "no height for " << text;
+    EXPECT_EQ(mac_width, canvas_width) << " width for " << text;
+    EXPECT_EQ(mac_height, canvas_height) << " height for " << text;
+  }
+
+ private:
+  Font font_;
+};
+
+ // Tests that Canvas' SizeStringInt yields result consistent with a native
+ // implementation.
+ TEST_F(CanvasTestMac, StringSizeIdenticalForSkia) {
+  CompareSizes("");
+  CompareSizes("Foo");
+  CompareSizes("Longword");
+  CompareSizes("This is a complete sentence.");
+}
+
+}  // namespace gfx