Merge change 599 into donut

* changes:
  Add call to (new) Canvas.freeCaches() in response to low-memory

core/java/android/app/ActivityThread.java

@@ -3496,6 +3496,9 @@ public final class ActivityThread {
             int sqliteReleased = SQLiteDatabase.releaseMemory();
             EventLog.writeEvent(SQLITE_MEM_RELEASED_EVENT_LOG_TAG, sqliteReleased);
         }
+        
+        // Ask graphics to free up as much as possible (font/image caches)
+        Canvas.freeCaches();
 
         BinderInternal.forceGc("mem");
     }

core/jni/android/graphics/Canvas.cpp

@@ -21,6 +21,8 @@
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkGLCanvas.h"
+#include "SkGraphics.h"
+#include "SkImageRef_GlobalPool.h"
 #include "SkShader.h"
 #include "SkTemplates.h"
 
@@ -58,8 +60,11 @@ public:
         return new SkGLCanvas;
     }
     
-    static void freeGlCaches(JNIEnv* env, jobject) {
+    static void freeCaches(JNIEnv* env, jobject) {
+        // these are called in no particular order
         SkGLCanvas::DeleteAllTextures();
+        SkImageRef_GlobalPool::SetRAMUsed(0);
+        SkGraphics::SetFontCacheUsed(0);
     }
     
     static jboolean isOpaque(JNIEnv* env, jobject jcanvas) {
@@ -933,7 +938,7 @@ static JNINativeMethod gCanvasMethods[] = {
         (void*) SkCanvasGlue::drawTextOnPath__StringPathFFPaint},
     {"native_drawPicture", "(II)V", (void*) SkCanvasGlue::drawPicture},
 
-    {"freeGlCaches", "()V", (void*) SkCanvasGlue::freeGlCaches}
+    {"freeCaches", "()V", (void*) SkCanvasGlue::freeCaches}
 };
 
 #include <android_runtime/AndroidRuntime.h>

graphics/java/android/graphics/Canvas.java

@@ -112,7 +112,9 @@ public class Canvas {
      * on behalf of the Canvas. Any subsequent drawing with a GL-backed Canvas
      * will have to recreate those resources.
      */
-    public static native void freeGlCaches();
+    public static void freeGlCaches() {
+        freeCaches();
+    }
         
     /**
      * Specify a bitmap for the canvas to draw into.
@@ -1405,6 +1407,14 @@ public class Canvas {
         finalizer(mNativeCanvas);
     }
 
+    /**
+     * Free up as much memory as possible from private caches (e.g. fonts,
+     * images)
+     *
+     * @hide - for now
+     */
+    public static native void freeCaches();
+
     private static native int initRaster(int nativeBitmapOrZero);
     private static native int initGL();
     private static native void native_setBitmap(int nativeCanvas, int bitmap);