[PPAPI] Add browser tests for compositor API

content/renderer/pepper/pepper_compositor_host.cc

Index: content/renderer/pepper/pepper_compositor_host.cc
diff --git a/content/renderer/pepper/pepper_compositor_host.cc b/content/renderer/pepper/pepper_compositor_host.cc
index 47c0fccfe6cb06198183de4377c305c91e2c0e9c..d04b9ff8cde3fa74b416839dca05b90f213200cb 100644
--- a/content/renderer/pepper/pepper_compositor_host.cc
+++ b/content/renderer/pepper/pepper_compositor_host.cc
@@ -10,6 +10,7 @@
 #include "cc/layers/solid_color_layer.h"
 #include "cc/layers/texture_layer.h"
 #include "cc/resources/texture_mailbox.h"
+#include "cc/trees/layer_tree_host.h"
 #include "content/public/renderer/renderer_ppapi_host.h"
 #include "content/renderer/pepper/gfx_conversion.h"
 #include "content/renderer/pepper/host_globals.h"
@@ -134,12 +135,6 @@ PepperCompositorHost::PepperCompositorHost(
     : ResourceHost(host->GetPpapiHost(), instance, resource),
       bound_instance_(NULL),
       weak_factory_(this) {
-  layer_ = cc::Layer::Create();
-  // TODO(penghuang): SetMasksToBounds() can be expensive if the layer is
-  // transformed. Possibly better could be to explicitly clip the child layers
-  // (by modifying their bounds).
-  layer_->SetMasksToBounds(true);
-  layer_->SetIsDrawable(true);
 }
 
 PepperCompositorHost::~PepperCompositorHost() {
@@ -157,7 +152,18 @@ bool PepperCompositorHost::BindToInstance(
   if (bound_instance_ && new_instance)
     return false;  // Can't change a bound device.
   bound_instance_ = new_instance;
+  layer_ = NULL;
+  layers_.clear();
+  if (bound_instance_) {
+    layer_ = cc::Layer::Create();
+    // TODO(penghuang): SetMasksToBounds() can be expensive if the layer is
+    // transformed. Possibly better could be to explicitly clip the child layers
+    // (by modifying their bounds).
+    layer_->SetMasksToBounds(true);
+    layer_->SetIsDrawable(true);
+  }
   return true;
+
 }
 
 void PepperCompositorHost::ViewInitiatedPaint() {
@@ -366,6 +372,11 @@ int32_t PepperCompositorHost::OnHostMsgCommitLayers(
       layers_.push_back(LayerData(cc_layer, *pp_layer));
   }
 
+  // We need force to commit on the parent layer, so the ViewInitiatedPaint()
+  // will be always called, even if all layers are not changed from previous
+  // CommitLayers() call.
+  if (layer_->layer_tree_host())
+    layer_->layer_tree_host()->SetNeedsCommit();
   return PP_OK_COMPLETIONPENDING;
 }