Support resize in Android Viewer App

tools/viewer/sk_app/android/RasterWindowContext_android.cpp

Index: tools/viewer/sk_app/android/RasterWindowContext_android.cpp
diff --git a/tools/viewer/sk_app/android/RasterWindowContext_android.cpp b/tools/viewer/sk_app/android/RasterWindowContext_android.cpp
index 306f291de8f80fadc10c5c2822a7b92b2b3096fa..3ba564635e2da2aeca87af682d3c6846e6185938 100644
--- a/tools/viewer/sk_app/android/RasterWindowContext_android.cpp
+++ b/tools/viewer/sk_app/android/RasterWindowContext_android.cpp
@@ -32,8 +32,12 @@ RasterWindowContext_android::RasterWindowContext_android(
     fNativeWindow = androidPlatformData->fNativeWindow;
     fWidth = ANativeWindow_getWidth(fNativeWindow);
     fHeight = ANativeWindow_getHeight(fNativeWindow);
+    this->setBuffersGeometry();
+}
+
+void RasterWindowContext_android::setBuffersGeometry() {
     int32_t format;
-    switch(params.fColorType) {
+    switch(fDisplayParams.fColorType) {
         case kRGBA_8888_SkColorType:
             format = WINDOW_FORMAT_RGBA_8888;
             break;
@@ -46,6 +50,17 @@ RasterWindowContext_android::RasterWindowContext_android(
     ANativeWindow_setBuffersGeometry(fNativeWindow, fWidth, fHeight, format);
 }
 
+void RasterWindowContext_android::setDisplayParams(const DisplayParams& params) {
+    fDisplayParams = params;
+    this->setBuffersGeometry();
+}
+
+void RasterWindowContext_android::resize(uint32_t w, uint32_t h) {
+    fWidth = w;
+    fHeight = h;
+    this->setBuffersGeometry();
+}
+
 sk_sp<SkSurface> RasterWindowContext_android::getBackbufferSurface() {
     if (nullptr == fBackbufferSurface) {
         ANativeWindow_lock(fNativeWindow, &fBuffer, &fBounds);