Added the QGC_GOOGLE_EARTH_ENABLED macro when that support exists.

QGCExternalLibs.pri

@@ -267,14 +267,16 @@ OSGDependency {
 # Only supported on Mac and Windows where Google Earth can be installed.
 #
 contains(DEFINES, DISABLE_GOOGLE_EARTH) {
-	message("Skipping support for Google Earth view (manual override)")
+    message("Skipping support for Google Earth view (manual override)")
+    DEFINES -= DISABLE_GOOGLE_EARTH
 } else:MacBuild {
     message("Including support for Google Earth view")
+    DEFINES += QGC_GOOGLE_EARTH_ENABLED
     HEADERS += src/ui/map3D/QGCGoogleEarthView.h
     SOURCES += src/ui/map3D/QGCGoogleEarthView.cc
 } else:WindowsBuild {
     message("Including support for Google Earth view")
-
+    DEFINES += QGC_GOOGLE_EARTH_ENABLED
     HEADERS += src/ui/map3D/QGCGoogleEarthView.h
     SOURCES += src/ui/map3D/QGCGoogleEarthView.cc
     CONFIG += qaxcontainer

src/ui/MainWindow.cc

@@ -679,7 +679,7 @@ void MainWindow::buildCommonWidgets()
     }
 #endif
 
-#ifndef DISABLE_GOOGLE_EARTH
+#ifdef QGC_GOOGLE_EARTH_ENABLED
     if (!earthWidget)
     {
         earthWidget = new QGCGoogleEarthView(this);

src/ui/MainWindow.h

@@ -61,7 +61,7 @@ This file is part of the QGROUNDCONTROL project
 #include "HSIDisplay.h"
 #include "QGCRemoteControlView.h"
 #include "opmapcontrol.h"
-#ifndef DISABLE_GOOGLE_EARTH
+#ifdef QGC_GOOGLE_EARTH_ENABLED
 #include "QGCGoogleEarthView.h"
 #endif
 #include "QGCToolBar.h"
@@ -416,7 +416,7 @@ protected:
 #ifdef QGC_OSG_ENABLED
     QPointer<QWidget> q3DWidget;
 #endif
-#ifndef DISABLE_GOOGLE_EARTH
+#ifdef QGC_GOOGLE_EARTH_ENABLED
 	QPointer<QGCGoogleEarthView> earthWidget;
 #endif
     QPointer<QGCFirmwareUpdate> firmwareUpdateWidget;