Move inval dedup to Window for wider usages.

tools/viewer/Viewer.cpp

Index: tools/viewer/Viewer.cpp
diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index c4b8b26dc51e3fda5a43a66962f5dba0a397de0d..acd9096182f6be10cade0b365807b286ad1d91be 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -83,7 +83,7 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
     // add key-bindings
     fCommands.addCommand('s', "Overlays", "Toggle stats display", [this]() {
         this->fDisplayStats = !this->fDisplayStats;
-        fWindow->inval();
+        fWindow->invalIfNeeded();
     });
     fCommands.addCommand('c', "Modes", "Toggle sRGB color mode", [this]() {
         DisplayParams params = fWindow->getDisplayParams();
@@ -91,7 +91,7 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
             ? kSRGB_SkColorProfileType : kLinear_SkColorProfileType;
         fWindow->setDisplayParams(params);
         this->updateTitle();
-        fWindow->inval();
+        fWindow->invalIfNeeded();
     });
     fCommands.addCommand(Window::Key::kRight, "Right", "Navigation", "Next slide", [this]() {
         int previousSlide = fCurrentSlide;
@@ -111,11 +111,11 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
     });
     fCommands.addCommand(Window::Key::kUp, "Up", "Transform", "Zoom in", [this]() {
         this->changeZoomLevel(1.f / 32.f);
-        fWindow->inval();
+        fWindow->invalIfNeeded();
     });
     fCommands.addCommand(Window::Key::kDown, "Down", "Transform", "Zoom out", [this]() {
         this->changeZoomLevel(-1.f / 32.f);
-        fWindow->inval();
+        fWindow->invalIfNeeded();
     });
 #ifndef SK_BUILD_FOR_ANDROID
     fCommands.addCommand('d', "Modes", "Change rendering backend", [this]() {
@@ -239,7 +239,7 @@ void Viewer::setupCurrentSlide(int previousSlide) {
     if (previousSlide >= 0) {
         fSlides[previousSlide]->unload();
     }
-    fWindow->inval();
+    fWindow->invalIfNeeded();
 }
 
 #define MAX_ZOOM_LEVEL  8
@@ -319,7 +319,7 @@ bool Viewer::onTouch(int owner, Window::InputState state, float x, float y) {
             break;
         }
     }
-    fWindow->inval();
+    fWindow->invalIfNeeded();
     return true;
 }
 
@@ -379,6 +379,6 @@ void Viewer::onIdle(double ms) {
 
     fAnimTimer.updateTime();
     if (fSlides[fCurrentSlide]->animate(fAnimTimer) || fDisplayStats) {
-        fWindow->inval();
+        fWindow->invalIfNeeded();
     }
 }