Bug 1415481 - set browser.tabs.drawInTitlebar to true on windows, cocoa and gtk3 widgets, r=dao,glandium

Enable browser.tabs.drawInTitlebar on platforms where CAN_DRAW_IN_TITLEBAR is set instead of the UNIX_BUT_NOT_MAC hack.

MozReview-Commit-ID: 9lko61izj4r

--HG--
extra : rebase_source : 98c1d9b8a89ec91c119634724187c614ea1d04f2

browser/app/moz.build

@@ -118,3 +118,6 @@ if CONFIG['MOZ_LINUX_32_SSE2_STARTUP_ERROR']:
 for icon in ('firefox', 'document', 'newwindow', 'newtab', 'pbmode'):
     DEFINES[icon.upper() + '_ICO'] = '"%s/%s/%s.ico"' % (
         TOPSRCDIR, CONFIG['MOZ_BRANDING_DIRECTORY'], icon)
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('windows', 'cocoa', 'gtk3'):
+    DEFINES['CAN_DRAW_IN_TITLEBAR'] = 1

browser/app/profile/firefox.js

@@ -470,10 +470,10 @@ pref("browser.tabs.loadBookmarksInBackground", false);
 pref("browser.tabs.loadBookmarksInTabs", false);
 pref("browser.tabs.tabClipWidth", 140);
 pref("browser.tabs.tabMinWidth", 76);
-#ifdef UNIX_BUT_NOT_MAC
-pref("browser.tabs.drawInTitlebar", false);
-#else
+#ifdef CAN_DRAW_IN_TITLEBAR
 pref("browser.tabs.drawInTitlebar", true);
+#else
+pref("browser.tabs.drawInTitlebar", false);
 #endif
 
 // Offer additional drag space to the user. The drag space