Android improvements:

runtime/embedders/openglui/common/canvas_context.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef EMBEDDERS_OPENGLUI_COMMON_CANVAS_CONTEXT_H_
 #define EMBEDDERS_OPENGLUI_COMMON_CANVAS_CONTEXT_H_
 
 #include "embedders/openglui/common/canvas_state.h"
 #include "embedders/openglui/common/graphics_handler.h"
 #include "embedders/openglui/common/log.h"
 #include "embedders/openglui/common/opengl.h"
 #include "embedders/openglui/common/support.h"
 
 typedef struct ImageData {
   int width;
   int height;
   GLubyte* pixels;
 
   ImageData(int wp, int hp, GLubyte* pp)
     : width(wp), height(hp), pixels(pp) {
   }
   ImageData()
     : width(0), height(0), pixels(NULL) {
   }
 } ImageData;
 
 class CanvasContext {
  protected:
   SkCanvas* canvas_;
-
   int16_t width_, height_;
-
   bool imageSmoothingEnabled_;
-
+  bool isDirty_;
   CanvasState* state_;
 
   static inline float Radians2Degrees(float angle) {
     return 180.0 * angle / M_PI;
   }
 
   inline void NotImplemented(const char* method) {
     LOGE("Method CanvasContext::%s is not yet implemented", method);
   }
 
  public:
   CanvasContext(int handle, int16_t width, int16_t height);
   virtual ~CanvasContext();
 
+  inline bool isDirty() {
+    return isDirty_;
+  }
+
+  inline void clearDirty() {
+    isDirty_ = false;
+  }
+
   inline void setGlobalAlpha(float alpha) {
     state_->setGlobalAlpha(alpha);
   }
 
   inline void setFillColor(const char* color) {
     state_->setFillColor(color);
   }
 
   inline void setStrokeColor(const char* color) {
     state_->setStrokeColor(color);
@@ skipping 99 matching lines @@
   void PutImageData(ImageData* imageData, float  dx, float dy) {
     NotImplemented("PutImageData");
   }
 
   void DrawImage(const char* src_url,
                  int sx, int sy, bool has_src_dimensions, int sw, int sh,
                  int dx, int dy, bool has_dst_dimensions, int dw, int dh);
 
   inline void Clear() {
     canvas_->drawColor(0xFFFFFFFF);
+    isDirty_ = true;
   }
 
   void ClearRect(float left, float top, float width, float height);
 
   inline void FillRect(float left, float top, float width, float height) {
     // Does not affect the path.
     state_->FillRect(left, top, width, height);
+    isDirty_ = true;
   }
 
   inline void StrokeRect(float left, float top, float width, float height) {
     // Does not affect the path.
     state_->StrokeRect(left, top, width, height);
+    isDirty_ = true;
   }
 
   inline void BeginPath() {
     state_->BeginPath();
   }
 
   inline void Fill() {
     state_->Fill();
+    isDirty_ = true;
   }
 
   inline void Stroke() {
     state_->Stroke();
+    isDirty_ = true;
   }
 
   inline void ClosePath() {
     state_->ClosePath();
   }
 
   inline void MoveTo(float x, float y) {
     state_->MoveTo(x, y);
   }
 
@@ skipping 60 matching lines @@
     return state_->setTextBaseline(baseline);
   }
 
   inline const char* setDirection(const char* direction) {
     return state_->setTextDirection(direction);
   }
 
   inline void FillText(const char* text, float x, float y,
                        float maxWidth = -1) {
     state_->FillText(text, x, y, maxWidth);
+    isDirty_ = true;
   }
 
   inline void StrokeText(const char* text, float x, float y,
                          float maxWidth = -1) {
     state_->StrokeText(text, x, y, maxWidth);
+    isDirty_ = true;
   }
 
   inline float MeasureText(const char *text) {
     return state_->MeasureText(text);
   }
 
   inline void Clip() {
     state_->Clip();
   }
 
   inline void ResetClip() {
     // TODO(gram): Check this. Is it affected by the transform?
     canvas_->clipRect(SkRect::MakeLTRB(0, 0, width_, height_),
                       SkRegion::kReplace_Op);
   }
 
   virtual void Flush() {
     canvas_->flush();
   }
 };
 
 CanvasContext* Context2D(int handle);
+void FreeContexts();
 
 #endif  // EMBEDDERS_OPENGLUI_COMMON_CANVAS_CONTEXT_H_