cc: Rework overlays to not use the ResourceProvider and pass texture size

content/common/cc_messages.cc

 // Copyright (c) 2012 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 "content/common/cc_messages.h"
 
 #include "cc/output/compositor_frame.h"
 #include "cc/output/filter_operations.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/quads/largest_draw_quad.h"
@@ skipping 836 matching lines @@
   }
 
   for (size_t i = 0; i < p.count; ++i) {
     LogParam(p.ids[i], l);
     if (i < (p.count - 1))
       l->append(", ");
   }
   l->append("])");
 }
 
+void ParamTraits<cc::StreamVideoDrawQuad::OverlayResources>::Write(
+    Message* m,
+    const param_type& p) {
+  for (size_t i = 0; i < cc::DrawQuad::Resources::kMaxResourceIdCount; ++i) {

[palmer, 2015/06/08 21:50:22]

I don't know cc well/at all, so this question might have an answer that is
obvious to those who do: What guarantee is there that |size_in_pixels| and
|allow_overlay| have at least |kMaxResourceIdCount| elements?

[achaulk, 2015/06/08 21:52:46]

They're defined as static arrays with that size. I suppose I could use an
arraysize() macro here instead though

[palmer, 2015/06/08 22:28:13]

Either way is fine, from a security point of view.

But, what processes formulate these messages, and what processes accept them?
I'm concerned about an untrustworthy process purposefully sending a malformed
object to this code. And, again, perhaps my concern is off-base.

[danakj, 2015/06/08 22:34:20]

The renderer sends them to the browser. If there are more resources in the
stream than this, they'd be read as other fields, and we validate other fields
as usual. That's the same problem as constructing any arbitrary stream. What
kind of problem are you imagining from using a constant here?

+    WriteParam(m, p.size_in_pixels[i]);
+    WriteParam(m, p.allow_overlay[i]);
+  }
+}
+
+bool ParamTraits<cc::StreamVideoDrawQuad::OverlayResources>::Read(
+    const Message* m,
+    base::PickleIterator* iter,
+    param_type* p) {
+  for (size_t i = 0; i < cc::DrawQuad::Resources::kMaxResourceIdCount; ++i) {
+    if (!ReadParam(m, iter, &p->size_in_pixels[i]))
+      return false;
+    if (!ReadParam(m, iter, &p->allow_overlay[i]))
+      return false;
+  }
+  return true;
+}
+
+void ParamTraits<cc::StreamVideoDrawQuad::OverlayResources>::Log(
+    const param_type& p,
+    std::string* l) {
+  l->append("StreamVideoDrawQuad::OverlayResources(");

[palmer, 2015/06/08 21:50:22]

Nit: could combine this with the "[" on the next line.

+  l->append("[");
+  for (size_t i = 0; i < cc::DrawQuad::Resources::kMaxResourceIdCount; ++i) {
+    LogParam(p.size_in_pixels[i], l);
+    l->append(", ");
+    LogParam(p.allow_overlay[i], l);
+    if (i < (cc::DrawQuad::Resources::kMaxResourceIdCount - 1))
+      l->append(", ");
+  }
+  l->append("])");
+}
+
+void ParamTraits<cc::TextureDrawQuad::OverlayResources>::Write(
+    Message* m,
+    const param_type& p) {
+  for (size_t i = 0; i < cc::DrawQuad::Resources::kMaxResourceIdCount; ++i) {
+    WriteParam(m, p.size_in_pixels[i]);
+    WriteParam(m, p.allow_overlay[i]);
+  }
+}
+
+bool ParamTraits<cc::TextureDrawQuad::OverlayResources>::Read(
+    const Message* m,
+    base::PickleIterator* iter,
+    param_type* p) {
+  for (size_t i = 0; i < cc::DrawQuad::Resources::kMaxResourceIdCount; ++i) {
+    if (!ReadParam(m, iter, &p->size_in_pixels[i]))
+      return false;
+    if (!ReadParam(m, iter, &p->allow_overlay[i]))
+      return false;
+  }
+  return true;
+}
+
+void ParamTraits<cc::TextureDrawQuad::OverlayResources>::Log(
+    const param_type& p,
+    std::string* l) {
+  l->append("TextureDrawQuad::OverlayResources(");
+  l->append("[");
+  for (size_t i = 0; i < cc::DrawQuad::Resources::kMaxResourceIdCount; ++i) {
+    LogParam(p.size_in_pixels[i], l);
+    l->append(", ");
+    LogParam(p.allow_overlay[i], l);
+    if (i < (cc::DrawQuad::Resources::kMaxResourceIdCount - 1))
+      l->append(", ");
+  }
+  l->append("])");
+}
+
 }  // namespace IPC