[Remoting Android] Fix OnPixelTransformationChanged Flakiness

remoting/client/gl_renderer.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/client/gl_renderer.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "remoting/client/gl_canvas.h"
@@ skipping 21 matching lines @@
 void GlRenderer::RequestCanvasSize() {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (delegate_) {
     delegate_->OnSizeChanged(canvas_width_, canvas_height_);
   }
 }
 
 void GlRenderer::OnPixelTransformationChanged(
     const std::array<float, 9>& matrix) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  if (!canvas_) {
+    LOG(WARNING) << "Trying to set transformation matrix when the canvas is "
+        "not ready.";
+    return;
+  }
   canvas_->SetTransformationMatrix(matrix);
   RequestRender();
 }
 
 void GlRenderer::OnCursorMoved(float x, float y) {
   DCHECK(thread_checker_.CalledOnValidThread());
   cursor_.SetCursorPosition(x, y);
   RequestRender();
 }
 
@@ skipping 38 matching lines @@
   // Set the background clear color to black.
   glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
   canvas_.reset(new GlCanvas(gl_version));
   desktop_.SetCanvas(canvas_.get());
   cursor_.SetCanvas(canvas_.get());
   cursor_feedback_.SetCanvas(canvas_.get());
 }
 
 void GlRenderer::OnSurfaceChanged(int view_width, int view_height) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  if (!canvas_) {
+    LOG(WARNING) << "Trying to set the view size when the canvas is not ready.";
+    return;
+  }
   canvas_->SetViewSize(view_width, view_height);
   RequestRender();
 }
 
 void GlRenderer::OnSurfaceDestroyed() {
   DCHECK(thread_checker_.CalledOnValidThread());
   cursor_feedback_.SetCanvas(nullptr);
   cursor_.SetCanvas(nullptr);
   desktop_.SetCanvas(nullptr);
   canvas_.reset();
@@ skipping 37 matching lines @@
 
   delegate_->OnFrameRendered();
 
   while (!pending_done_callbacks_.empty()) {
     pending_done_callbacks_.front().Run();
     pending_done_callbacks_.pop();
   }
 }
 
 }  // namespace remoting