Put the Pepper stuff in the content namespace.

content/renderer/pepper/pepper_platform_image_2d_impl.h

Index: content/renderer/pepper/pepper_platform_image_2d_impl.h
diff --git a/content/renderer/pepper/pepper_platform_image_2d_impl.h b/content/renderer/pepper/pepper_platform_image_2d_impl.h
index 333ee01c6267974b1e85ad906eca3e2f59590cb7..851689a0e4ac75a6348c24fb14685dae9861ebfc 100644
--- a/content/renderer/pepper/pepper_platform_image_2d_impl.h
+++ b/content/renderer/pepper/pepper_platform_image_2d_impl.h
@@ -8,6 +8,8 @@
 #include "base/basictypes.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 
+namespace content {
+
 // Implements the Image2D using a TransportDIB.
 class PepperPlatformImage2DImpl
     : public webkit::ppapi::PluginDelegate::PlatformImage2D {
@@ -36,4 +38,6 @@ class PepperPlatformImage2DImpl
   DISALLOW_COPY_AND_ASSIGN(PepperPlatformImage2DImpl);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_IMAGE_2D_IMPL_H_