DeviceOrientationDispatcher: no orientation updates equal to lastOrientation().

The DeviceOrientationDispatcher, which implements WebDeviceOrientationClient,
must not send orientation updates that are equal to its lastOrientation().
This can happen when the client is stopped and then started again.

BUG=44654
TEST=Manual

Review URL: http://codereview.chromium.org/3104038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57650 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 34 insertions, 13 deletions

diff --git a/chrome/renderer/device_orientation_dispatcher.cc b/chrome/renderer/device_orientation_dispatcher.cc
index 816cda8..edf9d03 100644
--- a/chrome/renderer/device_orientation_dispatcher.cc
+++ b/chrome/renderer/device_orientation_dispatcher.cc
@@ -50,24 +50,44 @@ void DeviceOrientationDispatcher::stopUpdating() {
 
 WebKit::WebDeviceOrientation DeviceOrientationDispatcher::lastOrientation()
     const {
-  if (!last_update_.get())
+  if (!last_orientation_.get())
     return WebKit::WebDeviceOrientation::nullOrientation();
 
-  return WebKit::WebDeviceOrientation(last_update_->can_provide_alpha,
-                                      last_update_->alpha,
-                                      last_update_->can_provide_beta,
-                                      last_update_->beta,
-                                      last_update_->can_provide_gamma,
-                                      last_update_->gamma);
+  return *last_orientation_;
 }
 
+namespace {
+bool OrientationsEqual(const ViewMsg_DeviceOrientationUpdated_Params& a,
+                       WebKit::WebDeviceOrientation* b) {
+  if (a.can_provide_alpha != b->canProvideAlpha())
+    return false;
+  if (a.can_provide_alpha && a.alpha != b->alpha())
+    return false;
+  if (a.can_provide_beta != b->canProvideBeta())
+    return false;
+  if (a.can_provide_beta && a.beta != b->beta())
+    return false;
+  if (a.can_provide_gamma != b->canProvideGamma())
+    return false;
+  if (a.can_provide_gamma && a.gamma != b->gamma())
+    return false;
+
+  return true;
+}
+}  // namespace
+
 void DeviceOrientationDispatcher::OnDeviceOrientationUpdated(
     const ViewMsg_DeviceOrientationUpdated_Params& p) {
-  last_update_.reset(new ViewMsg_DeviceOrientationUpdated_Params(p));
 
-  WebKit::WebDeviceOrientation orientation(p.can_provide_alpha, p.alpha,
-                                           p.can_provide_beta, p.beta,
-                                           p.can_provide_gamma, p.gamma);
+  if (last_orientation_.get() && OrientationsEqual(p, last_orientation_.get()))
+    return;
+
+  last_orientation_.reset(new WebKit::WebDeviceOrientation(p.can_provide_alpha,
+                                                           p.alpha,
+                                                           p.can_provide_beta,
+                                                           p.beta,
+                                                           p.can_provide_gamma,
+                                                           p.gamma));
 
-  controller_->didChangeDeviceOrientation(orientation);
+  controller_->didChangeDeviceOrientation(*last_orientation_);
 }
diff --git a/chrome/renderer/device_orientation_dispatcher.h b/chrome/renderer/device_orientation_dispatcher.h
index 0370f25..e2abf37 100644
--- a/chrome/renderer/device_orientation_dispatcher.h
+++ b/chrome/renderer/device_orientation_dispatcher.h
@@ -11,6 +11,7 @@
 
 class RenderView;
 namespace IPC { class Message; }
+namespace WebKit { class WebDeviceOrientation; }
 
 struct ViewMsg_DeviceOrientationUpdated_Params;
 
@@ -34,7 +35,7 @@ class DeviceOrientationDispatcher : public WebKit::WebDeviceOrientationClient {
 
   RenderView* render_view_;
   scoped_ptr<WebKit::WebDeviceOrientationController> controller_;
-  scoped_ptr<ViewMsg_DeviceOrientationUpdated_Params> last_update_;
+  scoped_ptr<WebKit::WebDeviceOrientation> last_orientation_;
   bool started_;
 };