Improvements to the SampleApp (primarily Android).

Reviewed at http://codereview.appspot.com/4587042/

Android
- Added buttons for interaction without a keyboard.
- Added the ability to zoom in to a specific point (roughly).
- Added event handling (for showing a slideshow, for example).
- Allow changing screen orientation
- Updated README file, explaining how to build

Multiplatform changes
- Added SampleApp header file
- Remove FPS when turning off measure FPS mode


git-svn-id: http://skia.googlecode.com/svn/trunk@1596 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/views/SkOSWindow_Android.h b/include/views/SkOSWindow_Android.h
index 569f3f7..e547609 100644
--- a/include/views/SkOSWindow_Android.h
+++ b/include/views/SkOSWindow_Android.h
@@ -18,9 +18,8 @@
 #define SkOSWindow_Android_DEFINED
 
 #include "SkWindow.h"
-#include "SkEvent.h"
 
-class GrContext;
+class SkIRect;
 
 class SkOSWindow : public SkWindow {
 public:
@@ -29,10 +28,7 @@
     bool attachGL() { return true; }
     void detachGL() {}
     void presentGL() {}
-    virtual bool drawsToHardware() { return false; }
-    virtual bool setGrContext(GrContext*) { return false; }
-    virtual GrContext* getGrContext() { return NULL; }
-    virtual void changeZoomLevel(float delta) {}
+
 protected:
     // overrides from SkWindow
     virtual void onHandleInval(const SkIRect&);