Allow WebExternalTextureLayers to receive a bitmap along with a mailbox

When using the software renderer, texture layers can't be drawn from directly. Instead allow the WebExternalTextureLayer to request a bitmap that will be used to draw.

BUG=151713

Review URL: https://chromiumcodereview.appspot.com/17859002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@210773 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 16 insertions, 4 deletions

diff --git a/cc/layers/texture_layer.cc b/cc/layers/texture_layer.cc
index fad7b13..eb00e53 100644
--- a/cc/layers/texture_layer.cc
+++ b/cc/layers/texture_layer.cc
@@ -172,7 +172,8 @@ bool TextureLayer::Update(ResourceUpdateQueue* queue,
   if (client_) {
     if (uses_mailbox_) {
       TextureMailbox mailbox;
-      if (client_->PrepareTextureMailbox(&mailbox)) {
+      if (client_->PrepareTextureMailbox(
+              &mailbox, layer_tree_host()->UsingSharedMemoryResources())) {
         SetTextureMailbox(mailbox);
         updated = true;
       }
diff --git a/cc/layers/texture_layer_client.h b/cc/layers/texture_layer_client.h
index b5c0de6..b9fc51c 100644
--- a/cc/layers/texture_layer_client.h
+++ b/cc/layers/texture_layer_client.h
@@ -25,7 +25,8 @@ class TextureLayerClient {
   // Returns true and provides a mailbox if a new frame is available.
   // Returns false if no new data is available
   // and the old mailbox is to be reused.
-  virtual bool PrepareTextureMailbox(TextureMailbox* mailbox) = 0;
+  virtual bool PrepareTextureMailbox(TextureMailbox* mailbox,
+                                     bool use_shared_memory) = 0;
 
  protected:
   virtual ~TextureLayerClient() {}
diff --git a/cc/layers/texture_layer_unittest.cc b/cc/layers/texture_layer_unittest.cc
index 39c0836..0f78b19 100644
--- a/cc/layers/texture_layer_unittest.cc
+++ b/cc/layers/texture_layer_unittest.cc
@@ -706,7 +706,8 @@ class TextureLayerClientTest
     return context_;
   }
 
-  virtual bool PrepareTextureMailbox(cc::TextureMailbox* mailbox) OVERRIDE {
+  virtual bool PrepareTextureMailbox(
+      cc::TextureMailbox* mailbox, bool use_shared_memory) OVERRIDE {
     return false;
   }
 
diff --git a/cc/output/software_renderer.cc b/cc/output/software_renderer.cc
index e7273a8..817bb67 100644
--- a/cc/output/software_renderer.cc
+++ b/cc/output/software_renderer.cc
@@ -76,6 +76,7 @@ SoftwareRenderer::SoftwareRenderer(RendererClient* client,
   capabilities_.using_partial_swap = true;
 
   capabilities_.using_map_image = Settings().use_map_image;
+  capabilities_.using_shared_memory_resources = true;
 }
 
 SoftwareRenderer::~SoftwareRenderer() {}
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index f3c262f..ff4d007 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -52,7 +52,8 @@ RendererCapabilities::RendererCapabilities()
       using_offscreen_context3d(false),
       max_texture_size(0),
       avoid_pow2_textures(false),
-      using_map_image(false) {}
+      using_map_image(false),
+      using_shared_memory_resources(false) {}
 
 RendererCapabilities::~RendererCapabilities() {}
 
@@ -683,6 +684,10 @@ void LayerTreeHost::CalculateLCDTextMetricsCallback(Layer* layer) {
   }
 }
 
+bool LayerTreeHost::UsingSharedMemoryResources() {
+  return GetRendererCapabilities().using_shared_memory_resources;
+}
+
 bool LayerTreeHost::UpdateLayers(Layer* root_layer,
                                  ResourceUpdateQueue* queue) {
   // If you change the name of this event or its arguments, please update
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index 3d114d5..b838aa2 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -80,6 +80,7 @@ struct CC_EXPORT RendererCapabilities {
   int max_texture_size;
   bool avoid_pow2_textures;
   bool using_map_image;
+  bool using_shared_memory_resources;
 };
 
 class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
@@ -255,6 +256,8 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
 
   bool in_paint_layer_contents() const { return in_paint_layer_contents_; }
 
+  bool UsingSharedMemoryResources();
+
  protected:
   LayerTreeHost(LayerTreeHostClient* client, const LayerTreeSettings& settings);
   bool Initialize(scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner);