Put the Pepper stuff in the content namespace.

content/renderer/pepper/pepper_parent_context_provider.h

Index: content/renderer/pepper/pepper_parent_context_provider.h
diff --git a/content/renderer/pepper/pepper_parent_context_provider.h b/content/renderer/pepper/pepper_parent_context_provider.h
index c749792aa65105f37cc41dfe02be7d18d82dae1e..abfeb2664df70b8e46764e2ed6a55f042619b347 100644
--- a/content/renderer/pepper/pepper_parent_context_provider.h
+++ b/content/renderer/pepper/pepper_parent_context_provider.h
@@ -10,6 +10,8 @@
 
 class ContentGLContext;
 
+namespace content {
+
 // Defines the mechanism by which a Pepper 3D context fetches its
 // parent context for display to the screen.
 class PepperParentContextProvider {
@@ -24,4 +26,6 @@ class PepperParentContextProvider {
   DISALLOW_COPY_AND_ASSIGN(PepperParentContextProvider);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_PARENT_CONTEXT_PROVIDER_H_