Initial pass at integrating Differ into the chromoting host code....

remoting/host/capturer_fake.cc

Index: remoting/host/capturer_fake.cc
===================================================================
--- remoting/host/capturer_fake.cc	(revision 55264)
+++ remoting/host/capturer_fake.cc	(working copy)
@@ -20,9 +20,26 @@
 CapturerFake::~CapturerFake() {
 }
 
-void CapturerFake::CaptureRects(const RectVector& rects,
+void CapturerFake::ScreenConfigurationChanged() {
+  width_ = kWidth;
+  height_ = kHeight;
+  pixel_format_ = PixelFormatRgb32;
+  bytes_per_row_ = width_ * kBytesPerPixel;
+
+  // Create memory for the buffers.
+  int buffer_size = height_ * bytes_per_row_;
+  for (int i = 0; i < kNumBuffers; i++) {
+    buffers_[i].reset(new uint8[buffer_size]);
+  }
+}
+
+void CapturerFake::CalculateInvalidRects() {
+  GenerateImage();
+  InvalidateFullScreen();
+}
+
+void CapturerFake::CaptureRects(const InvalidRects& rects,
                                 CaptureCompletedCallback* callback) {
-  GenerateImage();
   DataPlanes planes;
   planes.data[0] = buffers_[current_buffer_].get();
   planes.strides[0] = bytes_per_row_;
@@ -35,19 +52,6 @@
   FinishCapture(capture_data, callback);
 }
 
-void CapturerFake::ScreenConfigurationChanged() {
-  width_ = kWidth;
-  height_ = kHeight;
-  pixel_format_ = PixelFormatRgb32;
-  bytes_per_row_ = width_ * kBytesPerPixel;
-
-  // Create memory for the buffers.
-  int buffer_size = height_ * bytes_per_row_;
-  for (int i = 0; i < kNumBuffers; i++) {
-    buffers_[i].reset(new uint8[buffer_size]);
-  }
-}
-
 void CapturerFake::GenerateImage() {
   uint8* row = buffers_[current_buffer_].get();
   for (int y = 0; y < height_; ++y) {