Enable HarfBuzz by default everywhere except CrOS

ui/gfx/render_text.cc

Index: ui/gfx/render_text.cc
diff --git a/ui/gfx/render_text.cc b/ui/gfx/render_text.cc
index bf98bc0cde55524f3fba35a8657a9f3bf99e8600..3101c0455ca6c10b22d36698d5b95c8f24cc01a2 100644
--- a/ui/gfx/render_text.cc
+++ b/ui/gfx/render_text.cc
@@ -27,6 +27,10 @@
 #include "ui/gfx/text_utils.h"
 #include "ui/gfx/utf16_indexing.h"
 
+#if defined(OS_WIN)
+#include "base/win/windows_version.h"
+#endif
+
 namespace gfx {
 
 namespace {
@@ -393,16 +397,20 @@ RenderText::~RenderText() {
 }
 
 RenderText* RenderText::CreateInstance() {
-#if defined(OS_MACOSX) && defined(TOOLKIT_VIEWS)
-  // Use the more complete HarfBuzz implementation for Views controls on Mac.
-  return new RenderTextHarfBuzz;
+#if defined(OS_WIN)
+  bool default_is_harfbuzz = base::win::OSInfo::GetInstance()->version() <=
+      base::win::Version::VERSION_WIN8;

[msw, 2014/10/05 17:58:21]

Are you sure the sizing problem only affects windows 8.1 and not 8? Add a
comment referencing the blocking bug.

[ckocagil, 2014/10/15 19:50:44]

This should be fixed on both as of
https://crrev.com/ec562a798a1835e0383e83bae7dc71dffcfc5fb0

+#elif defined(OS_CHROMEOS)
+  bool default_is_harfbuzz = false;

[msw, 2014/10/05 17:58:21]

What is the chrome os blocker(s)? Add a comment referencing the bug(s).

[ckocagil, 2014/10/15 19:50:44]

Done.

 #else
-  if (CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnableHarfBuzzRenderText)) {
-    return new RenderTextHarfBuzz;
-  }
-  return CreateNativeInstance();
+  bool default_is_harfbuzz = true;
 #endif
+
+  if (!default_is_harfbuzz || CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableHarfBuzzRenderText)) {
+    return CreateNativeInstance();
+  }
+  return new RenderTextHarfBuzz;
 }
 
 void RenderText::SetText(const base::string16& text) {